the moment i do Alt+Return to put the mainrenderer
in fullscreen at the second head, keyboard(system global)
gehts the key outputnode as slice, like 0)alt, 1)return
but leaves the slice as output.
if i then press ALT once and then RETURN once, it switches
back to show crossed 0 and works again like it should.
so when it does not work, looks like radiokeymatch only
checks the first slice, finds no match, does nothing.
keymatch seems to check the last slice/or all and therefor
works without any complain.
so workaround is just pressing ALT and then RETURN, after
you switched to fullscreen and then it behaves as it should.