I could not do a Developer Beta upgrade on any of the systems I tried, all running macOS 26.5.1. Studio M1 Ultra (64GB/4Tb), mini M4 Pro (48GB/2TB), M4 MacBook Pro (24GB/2TB.) It failed during customization to the platform.
I ended up adding a Volume Group and installing a fresh copy. Probably smarter anyway. I do have full clones and TimeMachine for any wipe and restore. Since I cannot do a full setup (Migration Assistant) setting up a smaller config is a Royal PITA.
I ended up adding a Volume Group and installing a fresh copy. Probably smarter anyway. I do have full clones and TimeMachine for any wipe and restore. Since I cannot do a full setup (Migration Assistant) setting up a smaller config is a Royal PITA.