Once I've asked a general question about special characters, but I've not really pulled anything out of it.
So now I'm asking a very specific question.
I want to have Ctrl+e and Ctrl+y behave in insert mode as they do in normal mode.
Here's my main failed attempt:
inoremap <c-e> <esc>:<c-u>exe "normal \<c-e>"<cr>a
but clearly there are a few variations of it where I've tried to more
\, or to insert Ctrl+e by hitting it after Ctrl+v.
And even if the above command worked, I think it would have the problem of screwing up the undo sequence because it exits insert mode and then re-enters it.