We will certainly have a lot more flexibility in handling application of patches as soon as we get closer to a gating CI.
We should first make sure that Gitlab CI (directly or through custom runners, Travis, or cirrus-build) can cover all the scenarios and tests that Peter has in his CI. The main missing ones are NetBSD and OpenBSD builds, and various additional tests for warnings during builds, though there may be more. Once we do that, imagination is the limit. :-)
Peter can @bots try to apply pull request, if pull request apply and all ci tests passed, then the bot automatically merge the pull request and push to the mirrors.
We even doesn't need gitlab or other things, only need the bot to monitor the instruction from Peter.