I made a scala file that creates a just intonated major pentatonic scale like so…
! JImajorPenta.scl
!
JI major penta
6
!
1/1
9/8
5/4
3/2
5/3
2/1
Midihub uses this to create a C major pentatonic scale. What if I wanted a G major pentatonic scale? How would I make that?
Looks like we have to expose additional parameters for Micro Scale - the base note and base frequency. 
The Midihub can accept a scala file with up 128 entries, covering the entire note range. That means any pitch should be assignable to any key. I’m pretty sure it’d be possible to generate the correct scala file with the appropriate transposition to get any base for the scale, but didn’t yet find a quick way to do it.