Before cutting your own seam tape from cloth became fashionable, I first used 9 oz tape because that's all there was and later 6 oz and later cutting my own from cloth. Now there's 4 oz tapes. My point is that I would sand the tape edges and even the tape itself and 99% of the time I would get a totally clear wet out. I would actually taper the woven edges of the tape right down to nothing. So, at this point I would let it harden totally and do a sanding and wet out. I always found that when sanding into glass, I finish with a very fine grit like 220 or higher. I often wet sand with 300 grit and when you sand, since its wet, you can actually see it wetting out transparent. Then you know what you have before applying a coat of epoxy.

You may want to consider just strips of 4 oz cloth for the other side. I've done a tight butt joint on seam strips as well and they were totally invisible once wet out and sanded. You don't have to have one continuous piece.