I contacted Zynthian crew through a contact form on the website and they suggested that I should create a forum topic, so:
The question is about adding the support for Scala scale files.
As one interested in microtonal music I can imagine that it would be good to have a powerful machine utilizing 11-limit diamond scale for example
Possible to implement in future?
Not a Zynthian user yet, just considering 
So can’t contribute much here.
Best,
Stepan.
I doubt that the raspberry has enough power.
You have to create 16 channels of the maestro_concert_grand_v2_pb.gig [0] Instrument. Every channel listens to one MIDI channel. Thats because the earlier mentioned pitch bend message affects every note played back via this channel.
The ZynAddSubFx engine supports microtonal rescaling, although it’s not available in the zynthian UI but I’m not sure if it works with scalar files. The desktop ui does look like it can import .scl files though.
samplv1 appears to support it although that’s not an available engine yet.
And Pianoteq supports them as well, afaik.
We should see what engines do support microtonal tuning / MTS (MIDI Tuning Standard):
On a first fast overview:
ZynAddSubFX => FYI, currently you can load microtonal scale files for ZynAddSubFX from the Zynthian-UI. You only have to copy them to the right folder 
Pianoteq => We should check if we can load scala files to Pianoteq via command line. If not, it seems to support MTS (MIDI Tuning Standard), so we could use this way.
FluidSynth seems to support MTS …
Synthv1 also seems to have support
Check this out:
Regards,