Not to rotate. It does 8 hits without rotating and like 18 if you do? Frank's damage scaling caps at around ~12-15 hits if I recall, and the scaling difference on those 4-7 not-fully-scaled frank hits does more damage than rotating on the hyper. So, unless you don't plan to follow the hyper up with a standard combo, don't rotate.
For a followup, I'm gonna guess at how your assists might be used, and recommend a couple of L4 options. Both will work if you're back is to the corner, which often happens with good FFC resets;
1) FFC, H Tools OTG, sMHS, jMMHS, call nova and roll past them to put them closer to the corner, picture, nova hits, sS, jMMHS, call doom and Ground H Tools OTG(Doom stops them from rolling out) xx Tools Hyper. 8-900k, builds the bar for the hyper, simple and effective.
more optimal if it works, 2) FFC, H Tools, dash under if your back is to the corner, sMHS, jMMHS(ends in corner), jump + call doom, j.H Tools + Beam OTG, sHS, jMMHS, jump + call nova, j.H Tools + Nova OTG, s.M Tools, s.M Tools xx Tools Hyper
Frank will always do more damage if you can end it in a M Tools / L Tools xx Hyper; they do massive damage. Best way to do that is to save the groundbounce and end in j.H Tools > L Zombie Toss > M Tools > M/L Tools xx Hyper, but it's difficult to do that with FFC as you usually have to start with a groundbounce.
Another good ender is jMMHS, relaunch, jMMH j.M Tools, land, sS, jS, kneedrop-land, picture xx Hyper. But the jH -> M Tools won't work late-ish in the combo, so it works best with slow assists used to do sS, jS, jH Tools, sS, jS. Like drones.
The basic FFC BnB is just H tools, mhs, jMMHS, assist relaunch, jMMHS hyper, though. --- Prozac is a dick. But he's a great player. He's like the Kanye West of GameFAQs, if Kanye had talent.