If you don't mind having some scrap glass, you can lay a piece of glass over the coaming, put masking tape markers on it (painters tape works well for this, less sticky) then cut out the opening for the coaming and glass the whole thing with one piece. It'll be a bit fiddly because the glass will want to pull out of shape as resin is applied. Should be no issues with epoxy you've usually got plenty of time to work to get it smooth and straight.

Will be smoother than trying to piece it with strips of glass.

I'd razor cut the edge where the glass is de-laminated then feather that edge, might be a bit tricky if it's actually on the riser but it'll work.

Bill H.