Sure you could make them so that they lasted for decades, but I can't see any advantage weight wise, it's not like you are carrying them regularly some distance.
What advantage does it offer over two layers of 30mm PIR foam in a cedar and zinc sheet roof? I prefer to keep straps on over winter although a deep roof might help on a very windy summers day such as today.
My concerns would be damage from full supers being placed diagonally on upturned roof sides, gelcoat chips very easily on tight radius corners and you'd then have sharp edges. If using polyester resin then styrene will leach out, the effects on the bees unknown as far as I can tell.
Composites are on the surface not that eco friendly, mining and processing steel and zinc isn't either but the cedar and osb is sustainable, the galvanised sheet roofs last for decades The one thing composite structures do have is they will last a very long time if made properly with no real maintenance.
Not sure what the current recycling status is, but you can recycle reinforcement offcuts back to the manufacturers, but once resin is introduced then its realistically only fit for landfill as burning releases a heap of nasties such as dioxins. and the entrained air in a resin fibre mix is very low so its use for insulation is would be pointless. Shredded and used as a bulk filler in other composite products would work, but usually you want thick light cores and thin rigid skins. Dumping to landfill is what Lotus and TVR used to do with their resin impregnated offcuts. TVR is long gone and Lotus have outsourced panel production offshore so don't really have to directly deal with the problem. Reducing waste by mould improvements, exact sizing of reinforcements by automated cutting which together significantly reduce component trimming have helped enormously.
