convex-backend/LICENSE.md at main · get-...
https://github.com/get-convex/convex-backend/blob/main/LICENSE.md
just don't host convex-backend and sell it as convex platform. so long as what you're selling is your SaaS (which means you're sellting them an on-prem solution of web/mobile frontend+convex-backend) you should be ok.
I'd still wait for an official convex employee to answer tho
