CasaOS, ZimaOS, Cosmos Cloud OS, RunTipi, etc.

So, none of these are a true OS.  At best, some of them are trying to be an app suite built on top of a Linux distro.  Some are literally just an app you install on whatever Linux OS you want.

The thing they all have in common is they try to simplify setting up Docker apps through the use of an "app store" where you just click install and off you go.

They all have some serious limitations and disadvantages to anyone wanting even a slightly customized install for any Docker app.  Even trying to by-pass the store to install a Docker container directly can result in a mess.

Unless you want to run a bunch of Docker apps with the most generic settings possible and almost zero effort on your end, I say stay away.  Stay far, far away from these.  They're mostly going to hamper your efforts in the long run.