As Microsoft has decreed, that key sends LEFTMETA + LEFTSHIFT + F23
(usually across multiple frames) and the then the same in reverse when
released.
xkeyboard-config 2.44 maps this sequence by default to XF86Assistant but
for the use-cases where this does not work reshuffling the whole event
sequence is the best approach and that can easily be done with a plugin.
Note that this is the minimum effort plugin - it works for one
keyboard at at time (duplicate the plugin if two keyboards are needed,
or remove the vid/pid check) and it does *not* intercept the meta/shift
key presses and delay them, it simply releases them on F23 and then
replays the new sequence. Good enough for an example plugin.
Example sequence produces shift + a on press and releases a + shift on
release. Holding the key will thus produce AAAAAAAAA which is an
excellent summary of how this key was designed.
Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1352>
