Supabase and Webstudio claim to be Open Source products therefore an integration between the both makes much sense. Actually in a future of open CMS/backend integrations, Supabase is a clear candidate to be Webstudio compatible.
In Supabase's website integrations area (https://supabase.com/partners/integrations) there is a Low-Code section where visual builders like Plasmic are featured. Webstudio could position there as the Webflow alternative that could use Supabase as the backend layer.
Maybe having some kind of starter-kit for supabase or an integration guide could help push forward the collaboration between this two great products. At the time when the backend capabilities are ready, I really would love to try that kind of stuff with a little guidance for sure.

Cheers, congrats for the great work here and have a nice day!