I haven’t played with many because I simply don’t have the time between work (Google’s Piper and Git) and kids. Piper handles the monorepo by only offering files when requested by the file system at the specified commit (this is probably a gross or even incorrect simplification, but is how it presents to the user).
There are good reasons that one should keep the whole commit history to distribute a source of truth, but at the same time if one is going to place full trust in something like GitHub (as many do), there’s no reason that full trust can’t be given to a similar website that provides a Piper model with some mechanism to request more than one commit to be brought to local storage (to get more sources of truth).
End of the day, a large repo checkout is going to be limited by either your network, your CPU/storage to perform archive expansions, or frequently both. I get the impression that Android and Chromium are expanding faster than those other things are improving, but have no data to back that up.
