> I'd like to help with this, but I don't even know where to start with argumentclinic -- any points would be greatly appreciated

Are you asking about argumentclinic in general or something specific to this bug? If it's something specific feel free to ignore the following:

You can find a basic tutorial on argumentclinic here https://docs.python.org/3/howto/clinic.html#basic-concepts-and-usage

Essentially, you'll be adding something along these lines into _cursesmodule.c

/*[clinic input]
_curses.set_escdelay
    size: int
        bla bla description for size.
    /

One line description.

Extended description. Spanning over
multiple lines.
[clinic start generated code]*/

after which you can run `python3 Tools/clinic/clinic.py _cursesmodule.c` which will update the file and place the stub for the method in there.