i'm in your conscience
RSE can trade with each other, but there's only one person on Emerald. Then there's another on FR and two with Red and Yellow respectively. I'd hate to have to make people completely swap games when they .sav file swap. "i wuz in kanto now i'm in hoenn guyz omg!!" Alternate games in the sign ups would have been a good idea, which is what we did last year iirc.
If you're okay with swapping to RBY, that'll work. Dunno what to do about the person on FireRed though...
Also, the event can be extended if need be, but I think October 5th was long enough, especially with B2W2 release next month as well as a regular challenge event (which you'll have a month to complete unlike this one lol).