Interesting stuff! In the full sized cans world, where I used to hang out, balanced is the way to go. However, I have only been using 3.5 since I got into iems, and have no complaints.
Arguing balanced vs. single-ended is an incredibly pointless affair. It all depends on how the amp manufacturer implements each circuit. Sometimes a DAP will have SE and BAL outputs that sound the same, or that offer entirely different tonalities, etc. I’ve yet to find a trend that defines an SE sound or a BAL sound.