How do you deal with writing code with multicursors when you have to type the same thing multiple times? With monospace I just ctrl+alt+down a couple times on aligned text and then type. With proportional fonts I don't suppose it's easy to align text exactly, so do you just not use multicursors or is there a solution you came up with that works?

I’ve been a professional programmer for 17 years and have never used multicursors. I don’t even fathom under what conditions you’d want to. I use Find and Replace.

Everyone programs a little differently. I often use it when e.g. using intrinsics and I want to change types. Find and replace isn't especially helpful when they're different names with substructure you need to modify locally.

Yes and ctrl-V in vim would be super awkward.

I don't use multicursors much, not every year. I'm using emacs. I register a sequence of keys and apply it multiple times with control e, control e, control e etc.

Not sure it counts as "multicursors" but overwriting a rectangle using C-x r t (string-rectangle) is pretty handy in emacs.