Script creation of MIDI track w/ instrument in Lua

Goal: create a LUA-base session template script which can set up arbitrary MIDI instrument plugins (plus other processors) on each track. E.g., the script might prompt for the location of the Virtual Playing Orchestra folder, and then offer checkboxes for the various instruments and articulations. After the user clicks “OK”, the script populates the session with a track per instrument / articulation, using ‘sfizz’ as the instrument, and passing through the path to the SFZ file.

The problem now is that the Lua interface for processors / plugins only allows control of numeric parameters, so the path-to-SFZ parameter of the ‘sfizz’ instrument cannot be set. Other instuments expose different options, e.g. selection of sountfont on the ACE-Fluidsynth instrument, drumkit for DrumGizmo, piano/instrument model for Pianoteq, etc.