ok.
id say theres two ways to attack (maybe more). a...you can shape the bottom of the stringer to fit every nook and cranny. or....which is what id do, mix up some resin with milled fibers, cabosil maybe some chop strand(1/4 inch) and create like a thick putty. commonly referred to as peanut butter or poky(pu-key)
i would apply some putty where the stringer will go to fill any gaps from the strake. afterward create a filet or round out what ever poky squishes out. you want to create a contour or curve going from hull up the stringer. this will help the glass lay down better. hope you understand.
also, i havent seen stringers go up that far. id do some research...ask around....you may not need to go all the way up to the supports. just stop right before them....or right before it crosses the strake. im not sure how far forward those supports are in relation to the dash, maybe you do need to go that far.