As long as you can build up the
hull structure to spread out the loads better should be doable. Guessing G10
fiberglass board from McMaster Carr would be best. What about getting to the vberth/head? What about
keel bolt access and limber holes? I haven't looked at mine in this context as the cross beam is solid in mine. Bear in mind that the top of the
compression post must be solidly located anyhow, otherwise sail forces could push it sideways, crushing a weak
cabin top skin /structure.