I can describe which possibilities you have if you write the controller model.
In general, "using ACT" is possible with 4 approaches (only 3 are practical):
1) "Cakewalk ACT MIDI" plug-in
2) "Cakewalk Generic Surface" plug-in
3) my own AZ Controller plug-in
4*) using ACT C++ API write own plug-in
To work with VST mappings (independent from 1-4 plug-in choice) you will need AZ ACT Fix or MarKo ACT Editor (or edit XML manually). "Default" Sonar approach without external tools, while at least possible in Sonar 2017 (some long existing critical bugs was fixed), can be frustrating.