GSX supports the standard time acceleration of the sim so, it will work faster if you use that kind of time acceleration, which is the standard one.
However, from your reference of the "10x" time acceleration, it seems you are not referring to the standard time acceleration function of the sim but, instead, the Time acceleration setting in the GSX Settings page and haven't noticed it's included in a box named "Refueling", which means the two items there (minimum time and time acceleration), refers ONLY to the Refueling process.
This is in addition to the standard time acceleration of the sim so, if you use (for example), 4x as the sim "simulation rate" and 10x in the refueling setting, ALL GSX vehicles will be accelerated 4x, but the refueling will be 40x faster.
