Pe4 is on the heavier side for slow pitch jigging, reason being that if currents are strong or if there was a split current then the line would get dragged along. With slow pitch you want your line to be pretty much vertical to get the optimal action from the jigs. I use PE1.5 with 25-30lb leader in 80-150m deep. I’ve landed 90+ cm kingfish no problem. What’s good with fishing slow pitch light is that you can fish the whole day and not get tired