Public logo URL behaviour is inconsistent

[Kirby]

Affected version

2.3.3

Assuming a style that has variations enabled:

Only default image is entered
The alternative field gets set to the value of the default image upon saving

Only alternativ image is entered
The default field stays empty upon saving, no error message is shown
Logo image is broken in frontend depending on active variation

Both fields are left empty
No error message is shown
Logo image is broken in frontendend for all variations

Suggested Changes

1. XenForo should use the alternativ version as default if only alternativ is specified and vice versa (Preferred)
   OR
   XenForo should show an error that the configuration is invalid if one field is left empty
2. XenForo should not output logo HTML if both fields are empty (Preferred)
   OR
   XenForo should show an error if both fields are left empty