We asked peers who had done their own SOC2 and stole their answer: post-facto reviews. We do regular reviews on large components, like the Rust fly-proxy that powers our Anycast network and the Go flyd that drives Fly machines. But smaller projects like our private DNS server, and out-of-process changes like urgent bug fixes, can get merged unreviewed (by a subset of authorized developers). We run a Github bot that flags these PRs automatically and hold a weekly meeting where we review the PRs.
This is a nice idea - you can push to main, but the review still happens at a weekly session. This removes the slowness, but still makes sure that there is a shared understanding of what changes were made.