I'm not sure what the intention was for emulators when ParadoxKarl set up the boards, and I'm not very knowledgeable on emulator types. Probably best to ask him.
I haven't played much emulator myself but I'd assume it'd affect load times only (I don't recall getting much in-game lag). However the load times are already affected by which console you play on (I use the New 2DS XL so my loads are pretty fast compared to a normal 3DS or a DS), so if anyone were to ever upload an actual video of a run we'd have to consider timing it differently (i.e. listing time with and without loads, like many games do).
The Time Trial and Single Race leaderboards have had 1-Lap categories added (all existing runs moved to be under 3-Lap), with the requirement of video proof for Time Trial 1-Laps due to the way DKRDS saves times (1-Lap times aren't saved separately between Time Trial and Single Race, so SR times wil