Forcing people to use hacks is a bad idea in general, and there are
two practical problems with doing it for immediate XFB in particular:
1. It breaks the GC IPL, which some users run when launching games.
2. Competitive players don't necessarily want the lowest possible
latency - they might want the latency that's the closest to console,
so if they're playing locally with a low-latency monitor, they might
not want to use immediate XFB. (This isn't a theoretical concern -
I've seen Melee players want to increase their latency.)
Besides, it feels arbitrary that just these five specific games should
have immediate XFB forced on.