It looks like you can use a a Bluetooth adapter plugged into your server as long as the normal Bluetooth integration is disabled, the matter integration needs sole access. Then you'll just use the browser interface to provision something.

Much less convenient to provision things but worth it if you can avoid Google lock in.

Possibly. There's also the consideration that the Companion app dev is a paid employee. Does enough of the community demand this feature to be googless to justify the development of building a new system from scratch instead of using the drop in service module?

I would love a fully function play services free version of the app. But is there enough demand for their limited resources to be applied?

Maybe someday Google will push enough people too far. But here on Lemmy we are definitely not the majority, even in the home automation hobby.

I'm not sure how how the hardware works with the matter software. It's possible that they are even already working on someday for the Bluetooth proxies to work which would be a good compromise even if the phone Bluetooth is impossible to use without play services.