>>29298410Injection is actually slightly worse on digital copies. The use checksums or something so you can't change too much each time.
If you play on a physical copy, there's a chance the 3DS will think the cart has been removed when it really hasn't. If this happens, you automatically lose the match. That can't happen on a digital copy.
I think I'll still do all my injection on my physical copy, then just trade it over to my digital copy. It'll depend on how easy injection is though.