: What can I expect to happen if I don't. All looks fine now other
: than a dimply texture. I can sand it down but since this was a
: final fill coat, I would have to sand through some glass to get
: to the stuff that filled in the low spots. Not sure I want to do
: that.

Honestly you could try just roughing it up and putting another coat, but if you got orange peel then the reason is almost certainly because of the residue left from the mineral spirits causing adhesion issues... kind of like putting water on an oiled surface- it wants to bead up. The epoxy has the same reaction but it has more surface tension so it gets wavy- orange peel- rather than just beading up. The problem is that likely you may not have a real good bond, and down the road especially after you get some UV from the sun the fill coat may start to peel away or crack and cause a crackled finish.

Don't fret- at least it's just the fill coat and it's an easy fix. Besides, the more you sand the smoother you're making things. Maybe it will come out even better after the next coat.