AFAIK, the G6 Lite only has one memory chip, it doesn't have to copy anything anywhere, everything just loads directly from the cart.
I'm not sure that's right. I think the delay in loading GBA games is it copying from slow to fast memory (not sure of the exact types, although
http://wiki.pocketheaven.com/G6 suggests NAND and NOR flash). DS games can run directly from slow memory, hence they don't need to copy, but GBA games need fast memory.
That's why I say AFAIK.
I really wish that the G6 team was more forthcoming about information. You see, I can use the entire 4Gb for NDS games - so how much 'extra' memory is included for GBA?
Looks like we'll all learn together.