Allow fullscreen fails in R4.1

Quoting /etc/qubes/guid.conf:

# EDITING THIS FILE WILL NOT HAVE ANY EFFECT! It is not read by the GUI daemon
# anymore, and is left here for reference only. To configure the GUI daemon,
# use qvm-features (see 'man qvm-features' for details).

allow_fullscreen is not mentioned in the qvm-features manual, and setting qvm-features whonix-ws-15-dvm allow_fullscreen 1 and starting a dispVM which inherits the rule, I cannot go into fullscreen just by e.g. double-clicking on a HTML5 video. Doing this causes the window to freeze until I go into full screen with Meta+F in i3.
Going into full screen with Meta+F is a nice workaround nonetheless.

Have you checked:

The GUI configuration file /etc/qubes/guid.conf in one of a few not managed by qubes-prefs or the Qubes Manager tool

But I’m not a 4.1 user so I might be wrong.

The file states in R4.1 that #EDITING THIS FILE WILL NOT HAVE ANY EFFECT! and it looks like that’s the case.

There seems to be a lot of documentation that is not applicable for R4.1, but that is our curse for the time being. Hell, even with the documentation, I’ve encountered dozens of non-hardware problems since starting to use Qubes.

I see. Then I don’t know what it could be.