For the fascia I needed something that was both stiff and hard but also relatively light. Styrene is too dimensionally unstable, traditional molding or MDF was too heavy.   A trip through The Home Depots molding aisle turned up what I needed, 2 1/2 inch by 1/4 inch thick “lattice”.  After carefully cutting it to length I ran a bead of DAP adhesive caulk along the face of the foam and wood glue along the face of the outriggers.  I then tacked the lattice to the face of the outriggers using #17 by 1 inch wire nails (brads).  Things are looking good at this point as the bench work is very solid, even when pressure is applied to the edge and I’ve achieved the clean look I was after.