I think it must be a coincidence because as far as I know the glycin in FX-2 would not harden the emulsion more than the pyrocatechin in Pyrocat-HD.
Also, someone mentioned the issue of alkalinity earlier. It is true that a very alkaline developer will result in more gelatin swelling, and this could make the emulsion more susceptible to scratchiong. But both TFX-2 and Pyrocat-HD use potassium carbonate as the accelerator and should work at about the same pH. I don't know this for sure because I have never tested the alkalinity of TFX-2. If you have a way of testing it you can compare to Pyrocat-HD which works at about 10.9.
But I am just curious. How are you managing to scratch the emulsion side of film developing in tubes? In principle nothing should be touching the emulsion side of the film to scratch it. Or are the scratches on the base side? If so, check the tubes because you might have some kind of burr on the lips or inside that is scratching the back of the film when you load and unload it.