> The main limitation to use the limited C API for stdlib is Argument Clinic which attempts to always emit the most efficient code, like using the METH_FASTCALL calling convention and use private functions like _PyArg_CheckPositional() or "static _PyArg_Parser _parser".
PR-26080 adds the feature that Argument Clinic to support to use the Limited C API.
METH_FASTCALL is the part of the stable ABI in PR-23009.
Do we need convert METH_VARARGS and METH_KEYWORDS as the part of the stable ABI too(something like METH_FASTCALL)?