OK - an update. There is still a problem with Parking my Mesu in SGP. I noticed this last night when I let my 'Parked' scope cool down for an hour or so prior to imaging. I switched on the mount, but did not connect it. It became clear that the scope was tracking, despite it having been parked (in SGP) the night before. Of course, I did not notice this until I tried slewing to my target and the mount was so far off that Plate Solving failed (or at least I gave up once the count went over 1000).
So I tested this morning. If I park in SiTech then the scope parks and, when I power it back on again, it stays parked. If I park in SGP, the scope moves to the park position, but, when I power on again, it starts tracking immediately.
Buzz: I loaded your script into Maxim and when run from Maxim, it parks the scope and it stays parked after I power it on again. I could not see how to run the script by itself within SGP. However, I asked SGP to run it as one of the End of Sequence actions. It was during the day so I couldn't really do very much, but the script appeared to do nothing whatsoever within SGP. I don't know if that helps with troubleshooting.