a) obs is either the flatpak or this https://github.com/wimpysworld/obs-studio-portable or you can install it in a container and use/avoid whatever plugins you want b) there is an older offline image in our github releases, but after it's installed you have to enter in the terminal:
rpm-ostree update
rpm-ostree update
to get it up to date since it wont auto update. Also that older image installer doesn't scale well with the steam deck, having the buttons cut off requiring the use of the TAB key on a physical keyboard
Portable OBS Studio for Ubuntu bundled with 50 plugins - GitHub - wimpysworld/obs-studio-portable: Portable OBS Studio for Ubuntu bundled with 50 plugins
do you think bazzite will ever support opengamepadui if it ever gets to stable? the project definitely looks interesting, especially that it is meant to support plugins out of the box rather than hack it together with web code injection