My example above can be simplified a lot:
basic = mw.col.models.by_name("Basic")
basic_reversed = mw.col.models.by_name("Basic (and reversed card)")
info = mw.col.models.change_notetype_info(
old_notetype_id=basic["id"], new_notetype_id=basic_reversed["id"]
)
req = info.input
req.note_ids.extend([1720992551032])
mw.col.models.change_notetype_of_notes(req)