This is a PowerShell script that will modify the flight_model.cfg, specifically the line "interactive_point.1" to disable the standard MSFS GPU. This means that you will no longer be able to call the GPU from the ATC ground services menu, nor use the GSX GPU, and can only use the custom GPU that you turn on from the tablet EFB in the cockpit. This will allow you to turn on the GPU anywhere you park, regardless of whether the current parking spot has a GPU available or not. There is included a script to revert to the original, which will again allow you to call the GPU from ground services and GSX, but this will restrict the GPU to only be enabled when there is an available GPU at the current parking spot. According to the developer, this is a restriction from Asobo whenever using the default GPU services.
The readme file contains all instructions, as well as the script code.