As I stated in the github report, I really think UIDs hold C3 back in many ways. I understand moving everything to UUIDs can be a big change, especially for backwards compatibility, but the alternative is trying to do a band aid fix that will not work.
I full agree with Tokinsom here, UID shuffling makes C3 unusable with source control nowadays, which is a huge issue.
For backwards compatibility, UIDs can stay, and UID shuffling can also be kept for a while, but instances should start getting referenced using UUIDs or SIDs (like object types and other editor elements), especially internally.