Feature: vim smart semicolon?

Is your feature request related to a problem? Please describe.
I have worked with semicolon languages (C#, Typescript) more lately... this often requires the input of a line ending semicolon from inside brackets and strings. vims source is full of examples. Lets take:

  keys = ['A'];
  keys = ['A|']

which looks like so before, | = cursor.
Now you need to move 2 right/EOL and enter ";". I don't know a really good way to automate this "chore", see alternatives.

Describe the solution you'd like
A smart semicolon, built inside vim (meaning: working with repeat), where we can press ";" in the setting above and have it entered at EOL.
A basic solution could be a setting: vim.smartSemicolonFiletypes = ".cs,.ts"
which would always enter ";" at EOL for a given filetype (with some option to put it back to the orig place).

Describe alternatives you've considered
You can do a mapping like so, but that screws up repeat.
inoremap ; <c-o>$;
Since we can't map <c-;> (#5152 ), I don't see an intuitive way to have a normal ; and an EOL ; in insert mode.

There are extensions for smart semicolon, I tried two and did not get them to work. And if, I am sure they don't cooperate with repeat.

The issue names no files or tests; start by reviewing the existing insert-mode mapping and repeat behavior, using the inoremap ; <c-o>$; example and the related #5152 constraint. Define the behavior for configured filetypes and how the original insertion position is handled, with repeat compatibility as the completion criterion.