Thanks for the feedback. I was trying to use the technique Nick showed in his video, see link below.

https://www.youtube.com/watch?v=cjW7Vj7e-7c&list=PLnPW0gzxQ0Njas9MxSw-N2KIRunRRTNTO&index=1

I can't tell from the video how thick the coaming lip is or how large the radius is. I don't recall how thick I made the lip but I do have a flat outside edge so there is room to make the radius larger. I did roll the corners but not very much. I'll try that and see how it goes.

If I were doing that job, I'd put a few smooth layers of tape (masking tape will do) or some other support on the underside of the lip, 'hanging out' past the edge. Put your epoxy and glass on the upper side and let it harden. Remove the tape and clean up the overhanging edge of the glass (leave it overhanging, just sand off the sharp glass threads).
Then I'd turn the boat upside down and do the glassing on the underside of the lip, letting gravity help with the job.
Then trim the glass, leaving a clear glass and epoxy edge about 1/8" or more thick beyond the wood.

If I follow your thinking, there would be no fiberglass on the thin outside edge of the coaming lip. Is that correct?