When you open the link grandMA3 onPC 18.104.22.168 Clean Start on PC (Mac doesn't seem to have the same option) end up starting the desk with the EULA and Release notes but it loads the previous show instead of a blank new show like MA2 did.
Works on my PC. Check the Clean Start Link:
"C:\Program Files\MALightingTechnology\gma3_1.0.0\bin\app_system.exe" HOSTTYPE=onPC CleanStart
May be another installation path?
Argh, looking closer I see what happened. The PC that I wanted to Clean Start was Global Master and my Mac was the Slave. When I closed the Global Master the Mac became the Global Master and I had not noticed. Then When I ran the clean start I just noticed that it quickly says [NewShow] while displaying the EULA then when the Mac invited the PC it switched back to the previous show. so when I agreed to the EULA and dismissed the release notes I was back at my old show..
So, totally my fault.
My Link is slightly different from yours in that it has an extra pair of double quotes at the end but it still works.