The answer does not allow you to change it to another modifier, though - the original binding is "special" as it is not possible to enter that in the UI. However one can use xmodmap to make any key into the Super_L key. For example, I have swapped the "Search" key (which acts as Super on my Chromebook) with the right Control key, so that I get Search acting as Control and the right Control key acting as the menu key.
There is no need to mess with window manager configurations, as this is simply a job for xmodmap. On lubuntu 21.10, I am able to do the following:
Create .config/autostart/xmodmap-autostart.desktop
[Desktop Entry]
Comment=xmodmap autostart
Exec=xmodmap $HOME/.config/xmodmap
Name=xmodmap-autostart
OnlyShowIn=LXQt
Type=Application
Version=1.0
and create .config/xmodmap
remove control = Control_R
remove mod4 = Super_L
keycode 133 = Control_R
keycode 105 = NoSymbol
add control = Control_R
keycode 105 = Super_L
add mod4 = Super_L
The trick is using NoSymbol as I am trying to swap right control with the super key, but you can't do it all at once.
Super
key to open LXQt's menu? You want to set it to something else?Meta+Space
through the GUI. What difficulty are you facing?~/.config/lxqt/globalkeyshortcuts.conf
forpath=/panel/mainmenu/show_hide
and look in/usr/share/lxqt/lxqt-panel/mainmenu.desktop
which hasType=Service
andServiceTypes=LXQtPanel/Plugin
. Neither indicate a conventional command! Sorry I can't help more but I'll pass on your query to guiverc who is part of the Lubuntu team.