New build is up:
https://stash.reaper.fm/v/33037/CSI%20pre%20alpha.zip
Added support for MasterTrack.
Syntax for .rst:
MasterChannel
MasterFader Fader14BitFB -60.0 12.0 e8 7f 7f e8 00 00
MasterChannelEnd
Syntax for .axt:
MasterFader MasterTrackVolume
Don't forget to reduce number of tracks to 8 for the MCU.