> Anybody else make these mistakes? How did you trim off the excess hardened
> epoxy, is there a time saver here?

Hey Paul, by the immediate response to your post you can see that these "mistakes" are part of what makes these boats so great to make. you get to make a boat,make mistakes, make "corrections" , make modifications, make repairs.

My first excess epoxy remover was a 1x2" sanding block, I'm not that comfortable with a surform near 4mm plywood, now I use sander and sanding block, masking the area off reduces the chances for more mistakes while sanding.

Too much too little takes time to tell