I've done it both ways and didn't find pre-coating worth it for most cases. Yes, a flat piece of wood is usually very much easier to coat and sand than a curved one (especially convex), but after all that, you're not done with it. You still need to cut, form and assemble the pieces. Then you haveto glass the boat.Most epoxies require you to sand them before applying a new coat if it's been more than 3 days since the previous coat.

Another potential problem is that if the epoxy manages cures to its full hardness before you start bending the wood, it will make it stiffer and more difficult to bend.  And you still have to coat the ends where you cut the wood after precoating. So I didn't really find it to be a labor-saving thing.

A bigger labor saver is to put on only very thin coats of epoxy. 5 thin ones instead of 3 thick ones save epoxy and result in less globbing and sanding.

Have fun,

Laszlo

IMO I would not precoat. I believe you would lose the chemical bond of the epoxy layers when applying the glass because the precoat epoxy would be old and cured. If you are worrying about wood splintering while cutting panels just score the line with a knife before cutting.