I would absolutely do some clean-up, edge feathering prior to a second coat of epoxy wherever you have a overlap joint of the glass cloth.  It has been my common practice to do so. Of course try to damage/sand into the actual cloth weave in the area as little as possible, but smoothing things out a bit and getting rid of the random strings just allows the second and subsequent coats to go on much smoother and better.  I don't think it hurts that you inevitably will develop some minor small patches where you'll see some "white" develop from sanding into the wave ever so slightly, no mattter how carefull you are.  In most cases there are already 2 layers of cloth where this is happening and you are only touching the top layer anyway.  It all disappears again in the next coat of epoxy. That's one person's opinion - but my boats haven't fallen apart or broken, and the overlap joints do become nearly invisible after a few coats and sanding/final varnishing.

   Thank You. I went ahead and did some sanding, before applying the second coat, while I was waiting for someone to reply. You are right. This sanding did make the second and third coats go on easier. Using my orbital sander and lots of caution to avoid damaging the layers of cloth.