I haven’t tried this, but since lua is full-featured programming language, I wonder if it would be less accident prone (and more upgrade-proof) to write a single lua macro script that reads a key press directly from the keyboard and uses that to select the appropriate Dorico API command.
That way, if you assign a keystroke to run the entire script (not the default Ctrl-Sift-Alt-R but something like which is easy to find on US and UK keyboards) you could then have a whole new range of "two-key short cuts" without tinkering with the installation files - i.e. if you pressA the ` invokes the script, which reads the A (or any other key) does the corresponding action.