It’s not really even a true monorepo. Little known feature - there is a versions map which pins major components like base or cfs. This breaks monorepo abstraction and makes full repo changes difficult, but keeps devs of individual components sane.
This was done away with years ago. Components are no more.
There are still a couple of things that develop on long lived dev branches instead of directly at head, but my personal opinion is the need for those things to do that is mostly overstated (and having sent them cls in the past, it's deeply annoying).