The thing is, I don't think how good the opponent is matters more to SD than it already does to BS. To me matchup knowledge matters the most (especially in KL) when you're doing some kind of gimmick (either a move or a very unique string). In SD you're just maximizing the same opportunities you get with BS when you land a F221 which is a lot. For the sake of testing, play Sabbath but focus on spacing and punishing with F221, count how many you got compared to how many launchers you got and compare the damage you'd get if you were playing SD.Don't be afraid to use meter on tackle. It actually does good dmg now.
Idk man being able to whiff punish with f2/b3 is irreplaceable for me. I agree with sonicfox in that if you are good at spacing you should play Sabbath.
SD does feel alot easier to win with but I haven't rly played any good opponents.
If the opponent locked you out of every option Seeing Double has because he's good you're probably locked out of Black Sabbath strats by default. It's the same opportunity for landing damage except one variation does more and counts towards a KB, plus it has all the launching possibilities of BS.
To me it really feels like the mindset I have when I'm playing Kabal. Let them try to jump in or hit me with anything, I'll be stepping away and B12 they all they until they adapt.