Wonder this crap; I used years ModePro to promote Amiga modes to RTG in my A500T, to CV3D or PicassoIV. Very minor problems, caused by programs that were not totally OS happy, mostly AGA progs. All games that were supposed to work on RTG did work. And then some which were not meant to work did work on RTG (Civilization, Colonization). The biggest problem is HAM, as animations do look quite psychedelic...
But mode promoting was a vital part of the system - until I got PicassoIV Flifi to work on my A500T.