Good to know. Thanks.
I made a collision model for the A-10, but wasn't able to install it in RF-X. Maybe because the file is too big.
Here's what I did to get your A-10 in RF-X
First. You need to make a copy of the electric motor you use because it's not in RFX.
I made a copy of the electric motor in RF9 by selecting the motor and then I used the Copy button to save a copy of it in the RF9 engines folder. I added an "X" to the end of the name to save it then I MOVED that engine file from the RF9 Engines folder to the RF-X Engines folder then removed the "X" from the end of the filename.
RF9 Engine folder path
C:\Users\YOURNAME\Documents\RealFlight 9\Vehicles\Engines
RFX Engine folder path.
C:\Users\YOURNAME\AppData\Roaming\Knife Edge Software\RF-X\VehicleResources\VehicleComponents
Second. You need to modify and remove some physics entries.
I removed the Spektrum controller from all the flight controls and connected them to the standard servos because RF-X doesn't have the Spektrum controller. I also removed the Spekrum controller.
A quirk of RFX is it needs to have all the landing gear defined as Springy and I normally use Springy Scale Retract so I replaced your "gear selection" with Springy Scale Retract in the Landing and Steering gear. In RFX the wheel gets stuck in the ground if you don't do that. One of your existing gear was Springy Steel but it had problems in RFX so I changed all of them to Springy Scale Retracts.
Remove the Brrrrt (gatling gun) and the Smoke physics entries because RFX doesn't have guns.
All that was done to the A-10 in RF9 then I saved a new EA with the same name and used that to install the A-10 in RFX. But be sure to make the copy of the electric motor and then MOVE it to the RFX engines folder BEFORE you try to import the modified A-10 EA.
After that it flew fine in RFX for me. Let me know if you try it and have any questions.