There are a few ways you can generally tell. I’ve listened back to some recordings I’ve done myself for studio use, and the rnhp + clear used to be a fairly common thing I would use often, so generally I ended up using it on material that I was either there for the recording and know how it should have sounded and compare that to other experiences with amps. The other ther way is just hearing a recording though a multitude of different systems at different levels that’s well recorded, generally you can figure out how something was supposed to sound or the way space was intended to be recreated through comparing the differences in the experience with each different system, that can give you a rough estimation of what something generally should sound like but it will never be 100% accurate or anything like that (well rarely anything is 100% accurate lol, and that accuracy is only perceived by me anyways, so opinions on accuracy will naturally differ there with the material used, the gear used, and the experiences of the listener, etc)
The clear is also one of those headphones that it’s spatial recreation is impressive but not that organic at times, since I would say it’s a more spherical representation of space which is pretty engaging and holographic but it isn’t laying things out in a room and recreating an accurate space to the recording, so interesting but not lifelike, which I think the rnhp ends up causing the clear to have a more natural presentation of sound where it doesn’t exaggerate space or placement and tends to make the clear’s spatial recreation more in line with what the recording generally has to offer. To me accurate placement is something I would more use in reference to real life, as in how accurate does something place sound in space (or how well does the headphone recreate the space of a room or the sound of a room in a recording to be more accurate), and the closer it is to what something should sound like in person, the more accurate I would find that to be. For most it really is just going to come down to the simple question of “does this sound realistic or not” when it comes to discussing accurate placement.