Jinx is not amused by this statement

As some said, it’s fine!

I have it installed on my raspberry pi to run Jellyfin and a few other apps, and it’s been mostly stable. However I’ve had the same thoughts as you, so I can confirm that you won’t be able to learn as much with it.

Some of my other needs are hosted on a VPS without CasaOS, and that’s where I was able to learn most of what I know. It’s also where I spent the most time configuring and fixing incompatibilities.

I’d suggest that you keep CasaOS for the things you want to depend on, and start learning on another system without CasaOS by installing apps you’re interested to try out. This way you’ll learn about reverse proxies, certificates, docker, etc, without being afraid to mess up your current setup.