I think that mid screen you would only set this up at the end of your conversion, so you wouldn't be dropping damage but you'd be burning an extra bar to go for the cross up. I don't use it really I assume it can be blocked low wether you time it to cross up or not and I expect most to be blocking low and reacting to overheads but it's always nice to have more options.
Well, like bishbash said, you can still do it at the end of combos, which is where I always do it. So you aren't sacrificing any damage, just meter. And you keep them guessing. Yes they can hold down to block it or delay wakeup. If they are doing this you can go into free pressure with 332 or low grab to beat people holding down. There is much more to it than just the crossup b3 because that alone is sort of a gimmick.
You'd be sacrificing meter along with about 10% damage, so you would do for example: j3 MB predator pounce j1, 112 mb deadly hook, dash b3. you're taking a huge risk, this is more something to do in casuals, rather than a match in tournament. I'm not taking away from how cool the crossup is, i'm just saying wasting a bar of meter for something like that wouldn't fly in most matches
I think it's somewhat risky but it's also rewarding, like if you are trying to make a big comeback. It really messes with their wakeup inputs too. I think it's good to let your opponents know that you're willing to do this and once they respect it (hold down or delay wakeup), then it opens up all sorts of stuff for her. You can do low grab or hold b3 then dash cancel in and go into 332 etc. Players that use delayed wakeup tend to do it every time, so you could start by faking the crossup and just block and see what they are doing before you commit to it. Honestly, it's not as risky as you are making it out to be.