Just in case anyone enjoys a little bit of closure - Here is how this search ended.
TL;DR - Bifrost 2 → Asgard 3 = 
A bunch of years ago I set out to build a pretty solid WFH/Gaming station and tried out a number of different things - in the headphone space I Landed on the FiiO E7/E9 stack with AKG 7XX and a Blue Yeti w/ ATH-M50’s. Eventually turned that station over to the wife after getting an “in-person” job and she wfh more often.
Shuffled EVERYTHING around last year due to COVID (moved bedrooms, dining room, office etc to accommodate 2 perm work-spaces). Realized the FiiO gear had not aged well, built a new PC with the promise of “Isolated audio with dedicated processor combining ESS audio DAC with amplifier”!!! Well, it was much better than standard PC - out, but nothing like what I was hoping for.
Picked up a Drop THX789 thinking it would give me plenty of room to grow…
Tried line out → THX 789 (SE output only) and couldn’t stand to wear any of my headphones for any period of time - Suppose Garbage in = Garbage out. I dusted off the E7 (alone) and compared to the output from the 789 and was kind of suprised that I could get near the volume with much more dynamic sound. So I output from the E7 to the 789 and it just wasn’t pleasing at ALL. Grabbed the E9, and usd the E7 as DAC ONLY out to the 789 - still bad 
Decided to return the 789 and do more research. Ended up deciding on something from Schiit, probably an Asgard 3 or Jot 2. Just was overly confused with their DAC Lineup and was struggling with the BF2 pricetag.
Ended up deciding that I didn’t want to do the DAC upgrade path (after the 789 experience, I really didn’t want source to be my limiting factor ever again…or to even be a question) and was sold on the BF2 and was wishy-washy on the Jot2 (for future proof) or the A3 (I only use SE, and I enjoy a more lively Class A sound where I can afford it). Ended up reading through enough that I would get the A3 w/ the BF2 and Placed my order.
At the time I ordered, the A3 was shipping in 1-3 days and the BF2 was 3-5 days. Next day my order was “Bifrost 2 In Production” then “rolling back-order” two days later.
Found you guys 2 or 3 days after that (after getting through probably +60% of Zeo’s DAC/Amp reviews).
Decided to Cancel my Schiit order after a couple of UN-inspiring exchanges with their Customer Service. Quickly hopped on a Used A3 (thanks to this forum) and ordered a Topping D70s after several reviews suggested it was warmer than the typical topping sound.
A3+Topping D70s was an interesting combo. Not sure how to describe it - but it was definitely open, very dynamic, resolved parts of music that I really hadn’t noticed before and at the same time felt - off. Mind you I’m primarily using AKG7XX as a guide post b/c of how much time I have underthem.
One thing that kind of felt strange - there was always a hint of “hot signal” and I would hear some distortion where it didn’t belong. Suspected the 2.5v output may have been the culprate and put the D70s into Preamp mode and knocked it back to -10 and it actually helped, but didn’t fully resolve the issue. (output via USB/SPDIF - itunes/tidal all had the same issue).
Overall I was enjoying the experience - but really wasn’t taking full advantage of ALL of the features (digital readout of bit/sample was pretty cool though). I ordered a Modi 3+ while still in the return window - and was able to A/B a little. Physco-acoustics or not - I did perceive a difference between the 3+ and D70s.
–I felt there was a fairly similar sound signature; but, the D70s was more open (wider feeling), had better bass, dynamics and overall upgraded sound from the 3+ (but no where NEAR a $550 dollar price premium justification, to me). I was VERY happy to keep the Modi 3+ around until I could get a hold of a BF2. Actually starting to get excited about the prospect of a BF2 b/c of the insane value (to my perception) of the 3+!
Had a new Shiitt Order for a BF2 ready to submit when I figured - what the hell. Posted in the Buy/Sell thread that I was hoping anyone would be willing to part with a BF2, lol. Within a few moments - it payed off and I had a BF2 on the way 
This gave me some 1:1 time with the Modi 3+, and I was fairly impressed at the enjoyment I was getting. I compared it to line-out from PC, E7 and really REALLY was happy with the improvement (and the prospect of plugging it into my iPad Pro and w/e).
Once the BF2 arrived, I was able to listen/play around with it and do some light comparisons with the Modi. Immediately I enjoyed the return of low end, and how well it seemed to balance with what kind of felt like a mid bump I had been hearing from the A3. I know the K7XX have a mid focused (to me) sound - but It seemed softer, yet somehow more forward since getting the A3 (i have other cans, just wont bore you with those impressions today). The BF2 all of a sudden felt like I was listening to music again - not listening to my setup! There were tracks that I’d been criitcally listening to over the journey described here - and I would play them with the BF/A3 combo and I kept laughing b/c I’d somehow forget to listen for things.
Does that even make sense?
Some tracks are just songs I know and LOVE, but many others are tracks I listen to specifically to get to know gear. Tracks I’ve used since getting trained how to listen to gear back in the 90’s (way down deep, bird on a wire, Spanish Harlem, etc).
Back to forcing my self to listen to elements of a track, and not to the music, I noticed some pretty interesting things. On the 3+ I often feel myself getting distracted with some separated instrument or intentional Left to Right effect…or chord plucks that really stand apart. A trend started to emerge and vocals would sometimes fade and the music would take over, especially when things get hectic (think slipknot and 9 metal musicians contributing to the music at the same time). The Modi 3+ w/ A3 does a great job of not hitting that dreadful “Wall of Sound” effect too terribly bad that happens all to often with a track with Information Overload, lol.
With the Bifrost 2 - I don’t get the same starteling effect so (very) often like I did on the Modi. There are a could tracks that REALLY kind of make my eyes cross - or the acoustic guitar just bloom’s on the Modi - where on the BF2 it’s just so much more natural. Things feel right, and musical, and so-so enjoyable.
I’m pulling cables for comparison - so it’s clearly not a blind test; but, I continually find my self listening to the passage and being ready to swap on the Modi, then swapping to the BF2, listening to the passage and not realizing i’m 3min into the next track (or2). I honestly feel like I hear things on the modi that pop, that get missed on the BF2 - but for the sake of enjoyment!
Listening to some currently popular tracks - the modi is a little grating and I can hear the distortion “pop out” like I could on the D70s (when it’s on -10) - with the BF2 it’s not as noticeable and I find letting a “what’s hot” playlist stay on shuffle longer without getting annoyed.
Just working - the Modi 3+ will still pull me out of my train of thought now and then with some technical “wow” or extreme separation in the music I wasn’t expecting. With the BF2 I really only get pulled out of my work-flow when some thing just sounds so good that I remember to hit the ‘add’ button.
Some pending questions:
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I’ve gamed (FPS mostly as of late) with the BF2 and the D70s - too much time between to really compare BUT I’m digging how the thicker sounds come through on voices and guns. Foot steps sound a little heavier than I’d expect - but i’m not sure its NOT the game mix. So the question - With the extra ‘space’ and how details stick out more with the Modi 3+, not sure if I’d prefer to game on it or not!? (if yes, then I’m gonna keep 2 Dac’s on my desktop…wth)
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Originally thought I’d keep the Modi for my HT setup and feed it with Optical from my Desktop PC (20ft run and 2nd zone is actually powering a pair of Dali Lektor’s beside my desk). My Yamaha A2000 won’t play a digital signal to a 2nd zone for some reason…so digital to Modi to the yamaha gets around that. With as much as I enjoy the music from the BF2, I’m considering just running XLR output (to rca) to the A2000, OR running Pre-Amp out from the A3 and letting it give a nudge of Class A love. Either way - that kind of leaves the Modi3 odd man out.
—I suppose I could use it from a sonos connect to multi-zone amp (assuming it’s better than the Sonos internal DAC); OR use it as a DAC for my wife’s setup (or bounce it once they run out of stock at Schiit).
To round out my HP collection I’ve picked up a Drop Senn 58x (based mostly on description that it has more bass than the 6xx) and the Meze 99 noir (b/c I’m an Un-embarrassed bass-head that cannot justify the pricetag of Fostex TH900’s right now). They’ll hang out with Senn HD 590’s (20 yrs old), Senn 280pro, DT770 80, ATH-M50 and M50x (which i don’t like at all), Koss kph30i and a couple BT for travel (sony 1000xm3 and Senn Momentum 2).
I appreciate everyone in this forum, and especially the members that have allowed me to scoop up some Schiit while there is none to be had from the manufacturer! Also - the Anylitical vs Fun thread for getting me to think about what’s really important to me - The music <3!
Sorry for the dissertation; hope you stopped at the TL;DR 
I daily drive the Element II and one of my daily cans is the K712 pro, and I really like the experience