Btw, there's something else that may work in future for this use case. There's been some progress for Serial MIDI support, I think that there's a good chance that we'll have a firmware release that allows using it later this year. So if you really wanted, you could literally drill a hole in Alchemist, add a stereo jack and resistor for MIDI output and connect that to pedal's DIN MIDI input with adapter cable. This would require building a custom hardware with serial MIDI enabled.
Not sure if you're willing to perform such hardware mod, otherwise you could try some kind of adapter that has USB host on one end and serial MIDI output on another. They exist, i.e. this, maybe there are some cheaper options.