Speed Dialer cant angle

I have a set of quad SD lokbox fins that I want to use on a new shape. I had them set in a 5’8" double wing swallow fish before, and used what was the “natural” cant which seemed pretty extreme to me, like 7-8 degrees. By natural I mean that setting the fins in the boxes with the boxes on a level surface, and the fins firmly seated. There were other factors why the fish did not go well, but I believe a contributing factor was the extreme cant. Are they purposely set at this angle to deal with deep concaves, or are they supposed to be that much? I’m wary of making the same mistake again. Do I need to compensate and set the boxes angled deep on the inside edge to eat up some of that excess? These will be going on a 5"2" stumpy simmons-ish quad with a wide tail, double to single concave that’s fairly strong. Can anyone give me finsished angles off an actual Pavel quad fish or similar shape? Thanks folks!

6 degrees