xcape
2. 2. 2018https://forums.bunsenlabs.org/viewtopic.php?pid=66403
The idea is to patch ‘the usual’ openbox dual-key shortcuts to single key, examples (using stretchbang logic);
xcape -e 'Super_L=Super_L|space' &
will bring-up ob root menu on super-l release.
xcape -e 'Super_L=Alt_L|space' &
will run gmrun on super-l release.
You could put some of that in ob autostart.