This is inspired by fedora bootc ecosystem (like the bluefin forks).
General idea is that users can fork microshift-io/microshift, tweak containerfiles and files, add manifests, and set up a nightly build of "their own microshift" which would be used for automatic bootc upgrades (via bootc-fetch-apply-updates.timer and bootc-fetch-apply-updates.service).
I've already done some work and experimentation on my personal fork, see:
This depends on COPR work extended with nightly microshift RPM builds (See nightly-copr.yaml)