GSX doesn't do any kind of automation like that, with any PMDG airplane.
In fact, GSX doesn't do that on any airplane, especially 3rd party that are flagged to use custom electrical or custom fuel systems, and all PMDG (and others too) are all internally flagged to be like that, meaning GSX won't try to charge the batteries or really refuel the airplane, which is what it would do when using a default/freware/simpler plane.
Whenever you see some GSX automation, it's always done by the airplane code, which reads some custom GSX variables, and reacts on its own to do what it needs to do to adjust its own custom systems, like the external power, the battery or the fuel.
I see you use LINDA so, I guess you must have used a custom script that does exactly what the airplane is normally supposed to do ( when it integrates with GSX ), which is surely possible and, it's the only explanation why you had these features working on the PMDG 747, because there's no way you could have that with just GSX.
You mentioned LINDA "offsets" ( which are in fact PMDG/FSUIPC offset ), considering nothing in GSX interfaces with FSUIPC, it must be something related to a Linda script, which for some reason is not installed or it's not working or it requires some updates.
