I have the Bullit 125 (2017),and only used weed fins on it, due to local WA condtions.Last time out a great sesh with 7.3 and 40cm vector weed slalom,generally for blating around i don't use smaller than 6.6 or 7.0 on it with 36 JP weed.
Have used with 8.3 and 42 JP weed which works well.
I have lighter and racier boards which I have Tribal weedspeeds for but are all Tuttle box so unfortunately can't try, on
my bigger board 138l speedster 85 wide,I use 43 weedspeed with 7.8/ 8.3, for comparison.
I'm around 90kilo (after a big feed

),hope this helps