Looking at the video as best I understand the ability to change the settings is only active while you can access the standard link. Once you are out of standard link range the Plink and the RTGPS no longer talk back and forth. With loss of the two way link the Xmtr goes into high amplitude, short message, long space between messages operation. You drop out of flight management mode and into recovery mode. At that point everything is on automatic until you get back into two way link range.
Regards,
Thomas of the Decodings