So ignoring all the BS and getting back to the discussion at hand.
My MODII twin fins arrived yesterday. Gotta say for $60 I am super impressed, nice flex at the tip with good base stiffness. Less than half the price of the Soars I would love but I think they will go well.
Set them up in my 6'10" Cjet and have a question.
The Cjet is a square diamond shape tail, it has hard rails in the last 25% of the tail that soften to the nose.
Comparing this to say a similar length Morning of the Earth it has harder rails that look to be around 40% and a swallow tail and flyer that will add bite to a twin setup.
Without immediately hacking in a swallow tail on my board I'm thinking my best bet to give a bit of grip at the back end be a stabiliser.

Sorry big picture of a small fin, only about 110mm height.
My twin placement would be the same as the MOE board.
Be interested to get any feedback or thoughts on this? I know that others have run this arrangement and was wondering if I jump straight to the stabiliser or simply try the twin first. My thoughts are the stabiliser because I don't have as hard a rail or the flyers and swallow tail.
Thanks