Yes, I do this with Ansible :).

There are Flatpak modules and gsettings modules to set up Gnome to your liking.

I also build my own toolbox using ansible-container.

dotdrop, because different dotfiles per OS/hist is supported (I am usingfedora, Ubuntu, Debian, macOS but you can configure it as you wish).

NixOS is hard to explain.
I also did not get it at first, but got into a 101 session at cfgmgmtcamp last year and then it clicked.

I would suggest looking at YouTube videos like this one and try to understand what NixOS really is.

It is a pity really that it is not more approachable, the project would have more success if it is somehow easier to explain to others that are new to it :).

No issues running it in Flatpak so far for light gaming.