Quote from zeugnimod :

I guess that people DO know it but prefer TBOs.

There is a lot of people that doesn`t know that. Yesterday there was 2 drivers at least that didn`t know they could use GTR2 class.

I've seen that a few times as well. People only using the UFR/XFR because they think that's all they can drive; they don't seem to know about the the restrictions and the GT2 class at all