Re: how would i modify a bimini top frame?
Don't know if this'll work but here's my thought:
move the main bow anchor points to the bottom of your arch. You'd have to shorten the ends of both the main and secondary bows but the rear supports should be OK as-is.
Essentially, you'd be changing the angle of the main bow but leaving the curved points the same. That should give enough clear space at the sides for a grill.
What do you think???