I've taken a quick look at the code. It seems that the parameter list in
the GUI is automatically generated when one calls registerParameter().
Is there a way to add a text line in the GUI without creating a
parameter? That would be quite useful, as would being able to add a
simple line as a separator (i.e. separate Strokes section from
Construction lines section).



I believe this is not hard to add for people with better insight in UI related stuff, but it does not exist atm.
I went around this issue in sketch by putting the "common" text in the first label, but this is no good solution :-(