If you want to first test the .L in a controlled, known-to-work fashion, then try remapping the nexttrack / prevtrack buttons from the Kenwood or Rio remotes (just for fun). Those buttons are KNOWN to support "long" presses in hardware/software.

As of v68, remapping does NOT work for the Empeg front-panel buttons. I'll reenable that maybe when I get back in a few weeks, if there's any real demand for it.

Cheers