All your comments really makes me wonder if you really understood how GSX works, when the airplane refuels itself, because it really seems you haven't. Particularly all the reference about what "Units GSX should use", or if it should use a percentage level or an absolute quantity.
When the airplane is refueling itself ( "show default fuel/cargo dialog option Disabled, as in our default config for the PMDG 737 ), GSX doesn't use or care about which method you use to INCREASE the fuel quantity:
- If the airplane allows you to set the fuel quantity as a percentage, GSX won't care, as long the fuel quantity on board INCREASED after the Truck went in position.
- If the airplane allows you to set the fuel quantity as a Level in Kgs, GSX won't care, as long the fuel quantity on board INCREASED after the Truck went in position.
- If the airplane allows you to set the fuel quantity as a Level in Lbs, GSX won't care, as long the fuel quantity on board INCREASED after the Truck went in position.
GSX Fuel system read data from the simulator in USGAL, the trucks have their capacity expressed in USGAL and their pump performance (which ONLY is used to calculate how much time the Truck should stay when the "Always Refuel Progressively" option is Enabled but the airplane has loaded itself "Instantly ) is expressed in GPM ( USGALS/minute ).
This means, no matter which method or unity of measure the *airplane* let you use it, it won't make the slightest difference to GSX, since it's only reading data from the simulator in USGAL, and it calculates values only based on that, an increase is an increase so, as long you follow the procedure that has been explained so many times, including in the above video, GSX will always detect a Fuel increase IF it really happened in the airplane, and will show the Truck for as long it would have taken IF GSX was actually refueling, which is simply the amount of the INCREASE detected, converted into and USGALS, divided by the performance figure of the truck, which is expressed in GPM. That will be the amount of minutes the truck will stay.
How SimBrief has anything to do with this ? NOTHING, of course.
When the airplane "refuels itself" (again: "show default fuel/cargo dialog option Disabled, as in our default config for the PMDG 73 ) , unless the airplane KNOWS about your SimBrief flight plan by itself, you just can't use GSX SimBrief integration because the airplane is REFUELING ITSELF! so, whatever SimBrief integration you can ( or can't ) use, it won't have anything to do with GSX.
Because it seems to me, that by discussing about "GSX Units of measures" or "Simbrief", you changed the GSX internal configuration to Enabled GSX Refueling over an airplane that can't be refueled by GSX, like the PMDG. There is a reason why that option is Disabled by default, and it's just because while it might *appear* to kinda-work, in fact the PMDG doesn't expect to be refueled externally, resulting in several inconsistencies in its own menus, that's why we set the option to Disabled. With the Fenix A320 is completely impossible to Fuel the airplane from GSX, since it's likely using a completely custom fuel system that GSX just can't touch.
Basically, you can't just force GSX to refuel an airplane that *cannot* be refueled, as a way to use GSX SimBrief integration to be added to an airplane that doesn't have one. Or, more precisely, to be added to an airplane that doesn't have one AND cannot be refueled by GSX.
Because yes, of course, if the airplane you use has a 100% standard fuel system, it CAN be refueled by GSX, and in that case, you'll see the GSX refuel menu which has a series of pre-set quantities AND an extra SimBrief option, with the exact quantity you had on the flightplan.
