I managed to get Tart to build both public beta and dev beta macOS 27 VMs using the .ipsw files on a MacBook Pro M3 that I upgraded to macOS 26.6 beta 5. I've also installed beta 4 of the command line tools for XCode 27 and they are ok allowing me to continue to build the VMs. Just having issues now pushing config profiles to a VM enrolled to a Fleet MDM server. I can enroll, but I'm unable to get the push notifications in order for the mobileconfigs to be installed. Will raise a ticket for the APNs not working on macOS 27 VM.