As you say, that amount of dust pales in comparison overall. It's also not just fiberglass dust, it's glass encapsulated in epoxy so it's less irritating to skin than bits of glass. But you do want to make sure not to breathe it in or get it in your eyes.

The adhesive in plywood also dulls a blade, so you're going to be sharpening your plane anyway. A little more won't be noticed. If that bothers you, the bevels can be done with a sander or even a sanding block, albeit at the cost of more dust. But you have a dust handling strategy already, right?

If the tape ends are rough, nothing says you can't sand them smooth. However, trying to bevel unjoined panels is an unneccessary level of complication that could mess up your build. Just do what the manual says. There's a good reason for it.

As far as the puzzle joints go, I like to give them a coat of unthickened epoxy along the edges first, let that soak in for a few minutes, then proceed on to the thickened epoxy that is the actual adhesive. This makes sure that I don't get an epoxy-starved joint. And yes, unthickened epoxy is what's always used to saturate glass, never thickened. Glass does not absorb thickened epoxy well.

The moral of the story is don't worry, be happy and follow the instructions in the manual. The folks who wrote that thing know what they're doing.

Laszlo

Incredible reply, Laszlo!  Greatly appreciated.

I strongly suspected that I'd interpreted the manuals/video correctly (i.e., that gluing/glassing should precede beveling and that this doesn't present any major difficulties) and that my concerns weren't valid, but that little voice in the back of my head kept imploring me to confirm with a seasoned veteran.  I certainly respect the accumulated wisdom that the manual represents and plan to follow it as my trustworthy guide.

I do need to work on that dust-handling strategy.  Aside from the idea of attaching a hose and vacuum to the (still imaginary) random orbital sander, I've been procrastinating on that question for sure but recognize the need to avoid coating my entire garage in a thick layer of dust.

A sharp block plane will create shavings when you bevel the edges.  The dust clouds will form when you start sanding the cured epoxy after fiberglassing...if you don't hook a vaccum to your sander!

   Before I added dust collection to my tools, I just opened the garage door and blasted a 36" fan down the boat blowing dust into the yard, driveway, cars, etc.  Before the fan, I just suffered. But a dust collector powered by shop vac sucks all the dust up making the shop much more livable.  Plus I wear a dust mask now. 

Work will dull the plane blade. That's why we have sharpening stones. 

If you pre-bevel the panels you will likely bevel them as if they laid flat on the table. But nothing is flat on a boat. Take a look at the deck to hull joint when you get the boat together. Pre-beveling will be wrong.