Do you know of any open source alternative to these? I'm not fully convinced by Umbrell so far
Discussion
Raspibolt and Raspiblitz are your best choices.
The former walks you through setup so you can learn command line, the latter is more rapid. Both have great support communities through telegram.
I don't have a Raspberry. I'm currently running Umbrell on a external SSD plugged into an old laptop running Ubuntu.
I take it it's not a common setup, but that's what I have for now, and what I'll probably have until the price of a RPi isn't 4x the retail price.