If you want to nerf capacity, then reduce the capacity per tank (though .. should probably nerf barrels then as well, and my 4 wagon crude trains only last 15 seconds when my factory is at full speed).
If you want to avoid dealing with the UI code, the community presented a a couple of nice compromises; always keep the tanks separated or create a single large capacity single tank wagon.
Unfortunately my use case for fluid wagons with separate tanks cannot be solved by adding more wagons. I need 14 independent tanks in the space of 5 rail cars to evenly feed 7 rows of heat exchangers with water. Maybe esoteric, maybe not common, but it's an example of a use that doesn't have a solution otherwise. Give people a creative option, and they'll find a creative use.
I know it's not meant this way, but this feels like a slap in the face. Nobody had any hint this feature was on the chopping block, that we shouldn't get use to it, and the original reporter of the bug in the UI sure wasn't intending to get the entire feature scrapped.
... also inserters shouldn't be able to compress belts.
At that point you might as well go all in on quantized belts. I want shed too many tears if this gets implemented, but it does sap a lot of the fun out of belt designs by trivializing them. It feels like perfect compression using a "dumb" inserter arm should be a little bit difficult, like with those perfectly timed designs that run all of the inserters on a precisely timed clock.
