@ttzz moving the fins on your 21 foot hull may change the feel of them at speed it should allow you to reset the original A K fangs also it puts the fins in more of a trailing posture rather than an aggressive one. The reason for all the different settings is to allow you to tune the system and get the feel that suits your needs as well as someone else with a different set of needs .
I suggest it just to see if you like it better nothing lost because you can always reset them to the more aggressive setting if you like.
Say you decided you wanted a less aggressive influence level at planning speeds but you want the slow speed docking and no wake control you have several settings to try so that you can achieve the most comfortable level of influence to fit your boating requirements.
If the fins were set all the way up they would have a smaller effect an planning speeds but still a good influence at slower speeds.
To me having the ability to steer off power is the most important feature I offer, if you can't control your boat at planning speeds when you decelerate rapidly you are at the most risk of collision and injury.
A few years back I recall we had someone locally accidentally pull the kill switch traveling under the bridge by fort Desoto boat ramp .
He was on a P W C with a passenger he struck the cement bases for the bridge pylons and died .
It took a while for them to determine that it was the lanyard that shut off the engine and he could not steer away from the impact.
I believe that in this case the weight of the passenger contributed to the death by crushing his ribs but the point is when something unexpected happens it sure is nice to have a way out.
You usually don't have time to think about it until later if you're lucky.
I used a 24 foot Yamaha with my ultimate steering and my early smaller fangs traveling at W O T with 3 people in the boat, pulled the throttles back to neutral and then had the driver do a right turn and then a left turn, his jaw dropped when the boat carved to the right and then to the left because he did not believe it would make the second turn, he does now!