yakaru

it's not 2021101301, it's 2021101300 (which crashes when you exit premium free, this was fixed in 01)

yes, you can adjust it yourself in the menu in bistrover (and p much every HD style before). but casthour makes that shit redundant for you by adjusting the offset automatically mid-song based on how you play, saving you one of the biggest headaches with this game, so yes, it is that good of a QoL feature to be considered that important

maybe if you read the remywiki page on CH about the new features, you'd understand. the big change is pretty much timing auto-adjust

did you actually try it? when i tried it literally the same way you just described, it just flat out crashed and it is most likely because these IIDX versions have different frame parts and animations (which are hard-coded) for each individual IIDX version, however I managed to make it work somewhat when I unpacked the ifs and individually replaced each texture and then repacked it again, but then I had the problem that Cannon Ballers had much more frame parts than the frame in Bistrover had, so there were tons of leftover textures that just couldn't fit into Bistro's frame, and it looked kinda terrible lol

that's not an asphyxia feature (to an extent, you can only toggle frames that have been included in the actual IIDX version), that's a feature of each individual IIDX version. IIDX 28 does not have the frame from IIDX 25 (or any other version for that matter, unlike IIDX 26), only the BPL ones are in IIDX 28.