The kits sell in enough quantity as they are Kelv and no body has ever returned one and said they dont work !!
Produce a GPN set-up and people will compare it to a GPA set up and slag it off.
Produce a GPA set-up and people will compare it to a WRC set-up and slag it off
Leave it as it is, and sell them around the world to those that want to use them is the option.
Mike Little used to run the works cars without ARB's until the GPA set up was developed and that was due to progress and adjustability requirements, not because they didn't work without !!