

Honestly, this seems more than your assumptions and fears than anything else.
Clients are open source and foss, the moment something strange is in, Headscale could adapt.
If they finally goes to full close source, then the community will fork (emby - jellyfinn drama).
Your arguments don’t hold together, for the good of the community
Precisely bitwarden movement proves my point. Bitwarden tried to degrade the features/compatibility of the solution and they couldn’t because of the vaultwarden implementation.
Can they always add new features after a pay wall? Sure! But once foss Sw is here it is simple impossible to remove functionality, at most, to get some coins for services not fully selfhosted.
If tailscale tries to do something similar is goint to be a shoot into their own leg, because all the sw already disclosed makes it impossible. Could they make the relay a paid one? Sure but then they will face the competence of a vps with the Headscale implementation.
This and only this is because in your home lab only foss Sw should be allowed, even if you need to pay some money from time to time