> "don't immediately trigger an expensive build process as soon as someone submits a pull request."

Yes, and I'd add to that "don't immediately trigger an expensive review process". There's no good reason maintainers should have to be on the hook for screening submissions from the entire general public (including all the various OpenClaws or whatever)... It's an absolutely unreasonable thing to ask of anyone. So Github has the opportunity to both protect their own uptime and do a decent thing for the community by solving this problem.