I made a mold 4 years ago and tried PVA, Mold release wax, auto wax etc. I also lent the mold out to people and it always comes back with a patch job. The bottom line is that mold release material works good if your mold is mirror smooth and usually works best with wax releasing polyester.

this year I coated my mold with a fairly thick coating of boat wax (very organic type not the white synthetic stuff). while it is wet (the wax) I lay on pieces of serran wrap and rub those in with more was on a rag. It lays a super conforming thin layer of plsastic and wax. The few wrinkels are really tiny - almost like hair line cracks.

I lay my seat up with epoxy and cloth and roving. One removed (easily) is sand the seat and give it a final brush coat of epoxy darkened with copy toner to make it black. It came out beautiful and released easily. My entire lay-up is done with darkened epoxy.

One more thing. I pull my seat off the mold as soom as the epoxy is not sticky any more. If you abondon it for thre days you may need a jackhammer - even with mold release stuff.

I once saw a video of making paddles in England. Professional fiberglass operation. Even they had a hell of a time cracking the paddle halves off the mold.