people will go to great lengths to not flash the receiver
Yeah, I'm sure that that'd go over well in every situation. "Hey guys, I know that you still have about 10 months of your warranty left for your DS lites, but I'd like to completely void that warranty - and risk bricking your DSs - just so we can play a game off of my flash cart"
Just because we're into the ROM scene, doesn't mean all of our friends are. I have no intention to void three 12 month warranties (24 month for a lot of Europeans) just to play a few games. However not every DS owner is going to say "Sure, I'm going to pay a lot of money to import some random Japanese game so we can play," so it's nice to go onto gbatemp.net and hear a few people saying Jump Superstars works.
Oh, and I don't think anyone's gotten Big Brain Academy to work with Download Play even with flashed DSs, so your compatibility list is wrong :-)
As for the list, I can confirm that Puyo Pop Fever and Jump Superstars work for me. Mario Kart freezes as normal.