No, it's not, since in MSFS adding things is a bit more complex than it was on FSX/P3D (it would require updating the layout.json too).
The easiest solution would be simply renouncing to an operator you don't use, possibly one that has a base color similar to your VA, and replace its logo here:
\Addon Manager\MSFS\fsdreamteam-gsx-world-of-jetways\SimObjects\GroundVehicles\FSDT_Staircase_TLD_ABS-580\texture\GSX_Logo_4x1.PNG.DDS
The texture must be in DXT5 using BC7 compression, with MipMaps. And, you must understand if you place a custom texture there, it will be overwritten each time you run the FSDT Update.
