I would love for these numbers to be right but they are not sadly, I'm positive on my claim and will go into detail.
Testing against corp charge means anything that leaves the character hitting Lex with +1 advantage and an attack that starts up at 6 frames will beat it out, in Flash's case his fastest most practical attack being 7 frames (d1) we would need +2 advantage. Clean B22 on block being +3 means our d1 beats corp charge every time but trades with d2 due to having 9 frames of start up. So with our sweep having 11 frames of start up we need to have +5 advantage to just trade with corp charge. So let's dive in to some of my tests for a better insight on why I show interest in proving some things.
I assume you mean 1,1 sweep gets punished as a frame trap versus corp charge, but my friend it actually trades with corp charge meaning 1,1 is +5 on block (for some reason it's listed as +7 tho, I assume my executions off).
With the same test you did with B22RMSC sweep hits Lex out of his corp charge consistently with the perfect execution but anything higher than 11 frames (sweep start up) get's wrecked, so we gotta have the frame data stand at +6.
B22F3RMSC can be just as effective in the corner but no so much mid screen compared to B22RMSC. Testing B22F3RMSC in the corner it traded every time with corp charge with sweep leaving the advantage at +5. Now that sounds great for Flash but the push back limits some options such as grab, 50/5o with d1d2 (d1 will whiff due to distance) and the chance of b22 whiffing on certain small characters due to distance (freaking hit box). Good thing you mentioned B22F3RMSC forgot to consider it in my reply due to it being a good option, however B22RMSC still outclasses it in almost every area of use. Still, should be learned.
F2RMSC is +2, tested versus Black Adam's d1 which is 6 frames versus a recorded Flash performing a perfect F2RMSC into d1.
What you can do with RMSC which is a bit of a gimmick but I find it outstandingly effective is d2RMSC. Usually they expect LK to make d2 safe, but couple that with sonic pound (12 frame gap) and RMSC (-5 on block) they are forced into a mind game of either trying to bait or punish sonic pound with a forward dash or anti air it, and d2 RMSC into continued pressure due to them expecting the sonic pound. Finally they deal expect all this but LK can also be used to mix things up for either punishing their attempts to retort the sonic pound and RMSC or as a frame trap on its own with delayed lighting kick.