For the stable ABI: I see a way forward, but with how things are interconnected I’m having trouble pinning it down and breaking it into pieces that are PEP-sized or smaller. See Pre-PEP: PyModuleExport -- a new export hook for modules for where i am now.
Given what I emphasized there, I think Phase II should be started in an early alpha release. That is, announce it now, but for 3.15.
Sorry for pushing back! I fully realize the sorry state of stable ABI for free-threading is partly my fault – looking back, I should have made it a bigger priority.