Ah, I see! That's where I adopted a repo of repos approach
https://raffertyuy.com/raztype/repo-of-repos-pattern/
Eventually I can prepare a sandbox per repository or per "whole project" as we call it.
It's fascinating as a problem - thanks for sharing!!!
A lot of work me and my fellow engineers do spans weeks if not months, tens of code bases, tickets etc. Having longer lived sandboxes that cover N repos in which you can just let experiments exist, together with plans etc is a superpower.