I'm quite happy with my start9. Fully open source code (FOSS). It runs on a lenovo tiny 24/7 since months. Pretty stable with no issues so far. They have a own marketplace for various apps and you can side load different apps built from community.

All that said, I can't say much about umbrel cause I never used it. Code is only source viewable.

No matter what your decision will be, I encourage you to separate your bitcoin stuff from all the other services.