Flashing modifiers (Alt and GUI) used in mod-morph trigger menu on Windows

[drewlwhitney]

I have this mod-morph:

q_kill: q_or_kill  {
    compatible = "zmk,behavior-mod-morph";
    #binding-cells = <0>;
    bindings = <&kp Q>, <&kp LA(F4)>;
    mods = <(MOD_LGUI|MOD_RGUI)>;
}

On Linux, this works as expected. On Windows, however, this causes the app menu to pop up, as if the GUI key had been pressed and released.

This seems to be because ZMK does not properly suppress flashing modifiers. If the GUI key is used in a mod-morph, the proper steps would be:

tap a dummy key (i.e. LCTL)

unregister the flashing mods

trigger the mod-morph behavior

restore the modifiers

possibly tap the dummy key again

QMK has a DUMMY_MOD_NEUTRALIZER_KEYCODE config option that fixes this for key overrides. Could we have something similar?

In the meantime, are there any local fixes?