Off topic but are you using your Deck as your main pc then? How are you finding it?
Use podman + distrobox/toolbox to keep things and install packages - similar to Fedora Silverblue.
As I said my display situation is a bit weird. On the dock I have two 1080p monitors. KDE Panels sometimes disappear and need to be moved. https://i.imgur.com/Ipvj8L4.png (eDP is build in display)
Other than that there is a complete silence in my room and I don't need much stuff for web dev. The only desktop game I play is dota 2 and I can live with lowered gfx settings.
Ansible or scripts could recreate what you desire but I go the distrobox route.
I decided not to alter rootfs, so I left it in RO mode. Instead I installed everything I need via flatpak and installed homebrew to have a build tools, compilers and so on.
Using thunderbolt monitor makes it a decent work horse. Basically some days I commute only with steam deck to my office, because I have monitor, keyboard and mouse there as well.
EDIT: I work on 4K monitor. And by the way, I have a running VM on my steam deck just in case I need something extra.