Boom! 37 eurocents a pair, 2.2 EUR shipped (but really it’s less of the shipping per pair because I got 4 pairs + a bunch of PortaPro temple-pads from the same seller), feels more like a regular sponge that I don’t expect will rot away, sound is absolutely normal (no bloated bass, no loss of highs) aaand they’re color-matched for the first time in their lives. 
Can you imagine if they had always looked like this stock, including a grey wire? They might’ve never got as much of a reputation for standing out on your ears and looking super-dorky, who knows.
Next up in mods: since I was shocked to find out the BTR3 has been underpowering them all this time, I need a better portable solution, and since no LDAC receiver-DAC-amp at a comparable price to the BTR3 seems to be able to put at least 100 mW into 32 ohms single-ended (my minimum I’ve estimated for these to get what they need at their 60 ohms), I may just have to replace their plug with a TRRS or pentaconn since thankfully the stock cable is already 4-wire all the way. (It’s either that or I’ll give up on BT and just get a mini smartphone that fits in my front pocket while I’m sitting down and I will power these from the HiBy FC3 in high-gain mode. Haven’t decided yet.)