I’ve had similar thoughts some several months ago, but I haven’t even figured out how to get a stable desktop environment in a VM (my experience with Linux is mostly in server-land). My overall approach for idempotency is a git repository that has a Terraform blueprint and an Ansible blueprint, and the whole kit is pointed at my home ProxMox cluster.
With this workflow I can lift and shift my entire localnet wherever I want in the future.
You could use a much simpler blueprint approach to accomplish your Desktop Environment VM. You’ll want to externalize any data that won’t get included in a blueprint rebuild (databases, games save files, media libraries, etc.).
The paint itself on the outside of the bottle cap. The ultra thin layer of (apparently polymer a.k.a. plastic) paint that make the cap not just metal colored.