Documentation - as is - is complete. [1] Full stop.
What follows is only an elaboration trying to clear up the confusion created by the wording.
[1] Unless there a bug reports.
You could completely ignore that sentence and pretend it doesn’t exist.
Why did I add it? I was pretty sure that if I didn’t add it a larger amount of people would get the impression that option “--template-standalone-upgrade” means “upgrade Standalones only”. That would be wrong.
“does not refer to “Standalone VMs”.” and it’s correct. Doesn’t refer to the topic of which type of VM (App Qube vs Template vs Standalone).
Option “--template-standalone-upgrade” is referring to a separate stage that is part of qubes-dist-upgrade. A stage that can be run separately, by itself. Dare I say “standalone”? (lower case, common English word, unrelated to Qubes VM type and certainly not referring to mixed case “StandaloneVM”)
Option “--template-standalone-upgrade does include upgrading both, TemplateVMs and StandaloneVMs.
I am not a fan of the changed terminology by Qubes. By renaming StandaloneVM to Standalone and thereby hijacking a common English word, a lot confusion can be caused.
Unsupported indeed.
That’s why High Level Overview exists.
So what I can say?
Just follow the steps and don’t try to find contradictions in the compatibility versus support matrix.
The problem is “compatibility” versus “support”.
- Qubes R4.2 + Whonix 17: compatible
- Qubes R4.2 + Whonix 18: compatible [A]
- Qubes R4.3 + Whonix 17: compatible [B]
- Qubes R4.3 + Whonix 18: compatible
So why are some combinations compatible but unsupported? Maintainability.
The definition of Undocumented, Untested or Unsupported Features includes:
This does not necessarily imply “technically impossible”.
When being on Qubes R4.2 with Whonix 17 and upgrading to Qubes R4.2, users indeed end up with Qubes R4.3 with Whonix 17 in a state of “compatible but unsupported”. But it’s only for a brief moment and fixed by Whonix release-upgrade. And this state, release upgrade is supported indeed in so far that reasonable efforts are made to correct fixable bugs, if reported.
From the perspective of Whonix 17 the underlying Qubes R4.2 to R4.3 upgrade “isn’t a big deal” because Qubes didn’t introduce breaking changes.
[A] sudo release-upgrade --force. That’s what I personally used during early Qubes R4.3 early RC (release candidate) development. There might even be Templates in Qubes community templates testing repository.
[B] Marek had built Templates during Qubes R4.3 early RC (release candidate) development. That was supposedly useful to ensure wide compatibility.