Re: Is there really a difference between regular Bondo and fiberglass reinforced Bond
That's where clean pepakura building can really make a difference. I resin the faceplate and other components in their correct places at the same time, and then separate them again. While separated, I resin the edges and lips that got missed on the individual pieces, let them cure, and then tape or hot-glue them back together temporarily for the bondo application. Applying the bondo and sanding with the pieces helps with the parallel surfaces and symmetry. You'll still have to apply bondo and sand out the meeting edges after the majority of the surfaces are done.
As for the edges that get bondo application, you can sand them sharp with a flexible block/etc... The thinner the bondo coats, the better. Edges that are bondo'd can still chip, but they are pretty durable, especially once primed and painted.