The problem is 4AB isn't safe either. You don't want to use it against Pie/Poe, Leixia, Patsuka, or anyone with a i14 punisher because it's really easy to see coming and you'll eat a massive punisher on block. There's more of a gap between 4A and the AA followup than there was for Sophitia, so it's really easy to tell the two apart for Pyrrha. So they'd just normally block high, but if they see a gap they'll switch to blocking low.
As for guard breaking, her best move is 66B BE (5), but the problem is against good players you'll eat a free punish for it. Which means you really only want to use it for anti-tech, whiff punish, or combo filler. That means they won't be taking the block damage. Her next best option is 4B(7)...but is extremely linear and easy to sidestep. Might be a good wakeup option though, or if you think you've got then turtling because of your pressure it could be safe to throw one out.
22_88B+K(9) is the next best option. It's safe on block (except for Patsuka's CE and Natsu's AA) but I haven't really used it much. The problem is you need to step first to use it, and off step you generally want to whiff punish. 44B+K(9) might be better, since you can throw it out as whiff punish after a backdash, but usually 44B or 44A is better because you want to do damage via their followups. 44B also breaks in 10, so you'd rather use that anyways.
6B+K(12) is highly linear, but it's safe. I prefer 3A+B(13) though, as it slighly tracks and comes out faster. 22_88A breaks in 15, but again, it's usually a whiff punisher. 6K breaks in 15 though, which is kind of surprisingly. Might be worth it to throw out a lot of 6K's, since it's safe on block and stuns on CH.