I'm having trouble understanding what you want.

Undo is for undoing an action, like inserting a bunch of text.

If you want to delete one character at a time backwards... use the backspace key?

Honestly the issue is mostly due to wanting a slightly smaller, but not one character, undo. I think the problem is just that the things that I view as pauses and separate actions are almost always shorter than what the undo function sees, and undo undoes enough that it's quicker to redo and backspace than retype.

> That's a more extreme version of the behavior I'm objecting to. Why would I prefer that?

Put something in the wrong place (probably via pasting, but it's not always clear to a screen editor if you pasted or just typed quickly)

Typically when I paste something, I type something beforehand, and then paste it in, undo it, and it undoes what I typed before.

This is worse when I'm using multiple cursors, which is usually me manually cleaning up some data.

Still use vim. You can use something like "5db" to delete the previous 5 words. For more precision, "5X" will delete your last five characters. And if you have a very specific use case, macros are a big help. If you have a very specific and recurring use case, you can script in vim script, ruby, perl, python (2 & 3), tcl, racket, and lua. There may well be support for others of which I am not aware.