Not only is L Cat Spike safe on block, but you can continue your block string with st. L since her jab is so fast and it could link into her Arrow Kick (a REALLY great poking tool imo)
Since Delta Kick can hit like a dive kick (top of head or at the feet) I bet you can get even more advantage. And with RB Neko Punch and Slide since they’re active for a while hitting at the end of the active frames would most likely reduce the disadvantage on block.
L Cat Spike +2 on block, +4 on hit. So best Hellcat to use would be M on block and L on hit leaving a single frame in between. That’s if you want to be lazy of course, L Cat Spike should but you within H Hellcat distance a lot of the time so it’s possible to time it with that for more damage
Most of the time I’ll cancel a blocked string into Delta Kick then go back to LMH and rinse and repeat, throw in a few assists in the middle and go for the occasional Hellcat
