I've read the rules, and it states that run-ahead isn't allowed if using Retroarch, but cannot see any mention of whether this is allowed for other emulators or not (perhaps I missed it).

Mesen has a run-ahead feature, if I set it to 2 frames it distorts the audio, but with 1 frame it seems ok. The input lag is honestly pretty bad, so I wondered if using this setting would be acceptable or not?

Thanks!