First of all, congratulations on getting such a great fighter!
As for the blocking, I can't say I have much experience with well timed blocks but I usually need to when I use Double and I don't want her element to change. You're kind of a sitting duck until the opponent charges you. Be especially wary of fighters that have a lot of projectile special moves like peacock and Parasoul, I wouldn't even bother trying to perfectly block those. So just make sure to keep an eye on their special move availability when you fight them. However, once any opponent charges you, try blocking right before they hit. It may take some practice and getting to know the AI, but it's not a bad starting strategy. Do be cautious of Big Band too, he may try something while charging and you don't want to accidentally hit him instead of block.
Hopefully this was at least a little helpful to you! Unfortunately I don't have a fighter that needs perfect block to work and the Devs haven't really specified what that even means but it couldn't hurt to give this a try and see what happens! Best of luck!