This is a seriously neat project. I've got to figure out a variant that will work on a WD12 (without dumping a hot lunch into my lap). Perhaps on a float next to the boat? I could start a pot of water boiling and call whatever jumps in Bouillabaisse :-)
I did have one thought about the construction, though. If builders are really in an all-fired hurry, once the fillets are applied they can be smoothed with a chip brush dipped in epoxy. It takes longer to write about it than to do it and leaves the fillets glass smooth. 10-20 seconds of smoothing eliminates many minutes of sanding without having to settle for a rough fillet in the interests of less time spent. Thanks for the project, John.