Hi Barry,
I am also facing your issue, I have been speaking with Gergely re: this issue and the thought is maybe in version 21. Graphisoft will create a do not run parameters option for a GDL object.
Until then though I am using a workaround which may work for you:
in the parameters place “AC_ProgramVersion” integer; set to “0”. then in the parameters script you can put
if AC_ProgramVersion > 0 then
endif
ArchiCAD places the current version number of the software in the parameters when it has been placed.
Hope this helps.