I am building my Zephyr right now. I bevelled the leading edge only but I contemplated bevelling the trailing and side edges. The hole in the fins is just a little too close to the edge for that. No rounded edge but a 30° sharp bevel. I have a B&D mouse sander that made the sanding work easy. I followed up with filling the surface and power sanding with 120 grit. I may come back with a 240 grit and touch it up but she looks fine to me.
So many people have left the edge squared off but I wanted to go a little further than "most people" because I prefer the aesthetics of the bevelled leading edge. Hey, nobody said we have to be the same!