The Correct Syntax for this command should be
http://<server>/cgi-bin/loadfile.cgi?action=startLoad&channel=<ChannelNo>&startTime=<starttime>&endTime=<endtime>[&subtype=<typeNo>]
It's possible, but you need to install google Store and so on.
we tested it with some Alarm Systems, also DMSS and no problems. Only thing is the tablet rotation, this sucks
As wittaj told you "Never change a running system", when you don't have Problems, than you dont need to update.
But FYI latest Firmware is V2.820.0000000.30.R.210508