I removed the lounge seats in my runabout from fiberglass floor and will replace with 4 pedestal swivel seats. I heard wood pieces fall down when removing the screws from loungers. Now I must use toggle bolts I imagine. My question: could I put down a "subfloor" of plywood for strength, drill holes for toggle bolts, then install pedestals? Reason: I'm not sure I trust 4 toggles alone to hold the pedestals in place and not rip out from the fiberglass. This is an older Shell Lake/Lund 16 footer--no way to get under the floor as is.