I've learned a few things to help me with my hit confirms, especially with Abby's st mp.
So I've started training myself to look at the stun bar. If that increases, then I know I got the hit and continue. A lot of players do this.
The second thing is just simple reaction, and I rely on that for ones that I feel I won't be punished as much if I don't land. So like Abby's st mp. If they block I can just mash again for a frame trapish sorta deal (unless they have a reversal or time their 3f well enough, or so the video says). Easier said than done with characters who have way faster normals.
Training yourself in practice mode and setting the dummy to random block could help train yourself to land them more often when reaction on hit, possibly.
Edit:Oh, I forgot. What were those fairly cheap monitors with minimal input lag? Time to pick one up before RB Proving Grounds and get back into training.