You're not missing anything, external control of the looper is still extremely limited.
Unless, according to the manual, you have the stompio which supposedly has the switches function as expected.
Switches 1 and 2 (individual tracks)
• Tap once: RECORD/OVERDUB/PLAY on the corresponding track.
• Double tapping: stop any playback or overdubbing on that track.
• Press & hold: erase the corresponding loop.
• Led modes:
• Off: the track is off.
• Green: tracks have content, but are stopped.
• Blinking red: the track is recording or overdubbing.
• Blinking green: the track is playing back.
Switch 3 (metronome track)
• Press & hold: activate/deactivate the looper metronome.
• Tap: when the metronome is ON you can tap tempo on this switch. Tapping tempo is only available when
no recording, overdubbing or playback is occurring.
• Led modes:
• Off: the metronome is disabled.
• Green: metronome is on.
Switch 4 (global track)
• Tap: START/ STOP for all the tracks. This is only available if there is something recorded in the tracks.
• Press & Hold: access the clear mode. To clear any of the tracks, do as follows:
1. Press & hold down the fourth switch.
2. Tap the tracks to clear all the layers recorded on the corresponding track.
3. Tap again the fourth switch to exit the clear mode
So the functionality exists, it's just not user programable.
Looking at the stompio manual, the single/double/hold presses send different cc#, so in theory all the secondary functions are midi controllable and assigned to specific cc#, but there is no way to reassign them.