Umbel was unstable enough for me at version 0.5 on a RPi4 w/ 4GB that I moved away from it and rolled my own setup with Proxmox and Docker. Got frustrated with the maintenance of that system after a year or so and went back to Umbrel (now 1.2) on an old 8th gen Intel mini PC w/ 16GB. performance and stability are way better now. I’m impressed with how far it’s come!