Fedora template upgrades: recreating DispVM Template vs 'rebasing'

[mvermaes]

Hello there.

When upgrading a Qubes 4 system to a new Fedora template, what are the differences between regenerating the DisposableVM Template from the new template using step 3 from [1]:

[user@dom0 ~]$ qvm-create -l red -t new-template new-template-dvm
[user@dom0 ~]$ qvm-prefs new-template-dvm template_for_dispvms True
[user@dom0 ~]$ qvm-features new-template-dvm appmenus-dispvm 1
[user@dom0 ~]$ qubes-prefs default-dispvm new-template-dvm

and changing the base template of the existing DisposableVM Template, either with Qubes Manager or:

qvm-prefs <existing-template-dvm> template <new-template>

?

I've run the four steps above to regenerate the DispVM Template during previous upgrades, but swapping out the base template also seems to work.

I thought the reason the additional steps were recommended in the docs might be to encourage periodically cleaning out/resetting unneeded software/data from the DispVM Template. But that seems like a good practice for AppVMs as well. I only have some light customization of Firefox and a few other applications in the DispVM Template, so I'm wondering if just changing the base template is appropriate for me.

Thanks!

[1] https://www.qubes-os.org/doc/templates/#switching