We had a 542 cc with a 135 opti. They are a spot on match for power and weight. Once up on the planing plank the tail will be trying to lift the motor further, driving the bow in and causing it to drive left and right - yes you are basically trying to power into a flat water broach which is dangerous. Turning the opposite way to stand it back up you'll find that one side of the fin is still underwater - again most unpreferred. That svdh hull is great to drive and extremely trim sensitive which is also excellent if you can steer a bit and throttle a bit and can see how a boat sits/should sit.
The back of a signature sits pretty low at rest because of the deep V. The opti should throw it onto the plane with a decent handful of throttle then back it off (or not). Those fins can be dangerous, especially if it is going to dig while trimmed out in a following sea or coming through a bar and the hull gets out of level. Short of a tinny buzzing around with a fat bastard in it (me) I think they have no place on a boat.
Ours had a fin on it when we bought it. It lasted one trip and went in the bin.