Saturn to PS1/2 Converter on Ebay

So this Sega Saturn controller converter is listed as being compatible with PS1 and PS2 systems, but the seller says it only works on PS1 games. Is this even possible? It seems to me that if a game supported PS1 controllers (meaning it does not need analog) then it should also support this. The seller does not have any fighting games to confirm. He said he's just going on what others have told him in the past.

Anyone know anything about this adapter or if it's worth taking a chance on hoping that it will indeed work with PS2 fighting games?

ebay.com/itm/192009714996?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT