Martin,
What you are experiencing is more drive due to added area and lift from the larger template asymetrically foiled fins.
This is good fun in weak waves and lower speeds.
As waves get thicker, meaner and or you are driving harder and faster, there can be a point where this will turn into too much lift, and you'll start to slide out.
That can be managed and fun or it can be a liability depending on the situation.
A fully developed agressive riding technique / approach will also reval this.
IE strong, fast, fluid, well rounded driving turns.
The fins that came with your board are a great general purpose temlate and foil combo. (way cheaper too)
The reason those fins appear to have more tow-in angle is because they are FCS side fins set in FCS center fin plugs. That's why the trailing edge doesn't match the pencil mark. The forward pencil mark gots lost when we drill out the front plug. I mark it with regard to the intended fin.
My rear fin temple is smaller than nearly all the FCS ones.
Other customers and team riders have also had great fun with the H2 templates.
But damn, .........they are EXPENSIVE!
