I'm sure you changed the controls for Milktris in the first place because people complained... but I sort of hate the new keybinds (though I do appreciate that there's now a way to speed up the fall of a piece without instantly dropping it).
The way I think about it, the right hand is used for manipulating pieces. To that end, "up" to rotate intuitively made a lot of sense. Up for instant-drop does not and I found myself instant dropping pieces I intended to rotate a lot. It's possible that I might get used to it with time... but it feels really awkward for now.
I would think that up=rotate, left=left, right=right, down=fastfall, space= instant drop would make most sense intutively. It might be worth considering the space bar for milking mode (more time sensitive than the instant-drop during milking scenes, at least, though less important in the warehouse scenes), but I think there's a sense of joy in slamming that final piece into place with the spacebar.
Again, I'm sure you've gotten complaints from people saying exactly the opposite, but I figured the more voices there are in the choir, the greater the chance that you can figure out what your playerbase wants.
