I plan to merge my following PR tomorrow. It adds a new Include/unstable/ subdirectory: move code surrounded by “#ifndef Py_LIMITED_API” to this directory, so Include/*.h would only contain the “limited API”. See the bpo for more details.
Note: I would prefer to post this message to a “python-dev” category. Committers is restricted to core devs (but everyone can read). IMHO my message doesn’t belong to “Users” or “Ideas”. But there is no “python-dev” category yet. If something creates it, I suggest to call it “Core Development” rather than “python-dev” since many newbies misunderstant the purpose of the python-dev mailing list