I hated doing it, DMG.
I don't know the exact mechanics behind the SDR Abuse either, but as far as I know, Diddy's dtilt, ftilt, and utilt (facing the opposite direction) should all clank with the SDR. I doubt that any of Diddy's smashes beat it, unless they are disjointed in a way that doesn't allow Sonic's hitbox to touch any of Diddy's hurtboxes.
But you DID say you get upset, which makes me upset, because there are BETTER things to get upset about than a Sonic abusing a lack of spin dash knowledge.
As for what's in my signature? Pure, animated, sexy gold.