It is not possible to interactively ask user for hostname while using username and password from autoinstall config

[Anton]

We used to have preseed config which allowed to interactively ask for hostname while keeping all other settings in preceed.
With subiquity it seems to be not possible.
We've tried
__
version: 1
interactive-sections:
    - identity
identity:
    username: username
    password: $crypted_pass
__
which gives parsing error because hostname is missing.

We also tried
__
version: 1
interactive-sections:
    - identity
identity:
    hostname: hostname
    username: username
    password: $crypted_pass
__
which opens profile setup screen with hostname and username fields pre-filled, but password field being empty

I've seen people having same issue here:
https://askubuntu.com/questions/1243679/ask-only-for-hostname-in-an-automated-server-install
https://discourse.ubuntu.com/t/please-test-autoinstalls-for-20-04/15250/298
https://discourse.ubuntu.com/t/please-test-autoinstalls-for-20-04/15250/349

[Joe Cooper (joe-virtualmin)]

This is the same problem as this issue from two years ago: https://bugs.launchpad.net/subiquity/+bug/1883180

I check in every six months in hopes that somebody has done something about it.