I know that the reg's states only two poles in use at one time, and there is a motion to make it up to 4 poles. I'm on my kayak the other day, and an old guy saw me come back to the launch and he said I have too many poles. I normally carry 4 poles pre-rigged for the day, when the line snaps on one, or if I see a different fish in the area...I can just grab and toss a different rig at it.
Normally one small fish pole rigged with a sabiki rig for porgies, one casting pole, one jig pole, and one set up for casting and jigging for a spare. In the winter months, I'll set 3 poles up for togs, using only one at a time, because once I break off a rig, wearing gloves, it is a pain in the butt to tie up another rig while trying to stay on the bite. Kayak fishing is a little bit different from boat fishing and shore fishing...since your getting wet and the weather doesn't like us most of the time. Also, while on a kayak....it's not feasible to use more than one line at a time unless anchored up and fishing for porgies and blues at the same time.
I've searched all the reg's for anything that states a max number of poles per/person per/vessel...and I can't find one.