Shower Waterproofing

New to the DiY world!!! Going to attempt to renovate small bath. Doing lots of research and have the help of a friend, which is nice. I'm trying to figure out the best and cost effective waterproofing for the alcove tub surround for a tile job. I'm thinking of going with GoBoard to due cost and ease of use from what I have seen. Though I have seen some test that show there can be seepage/absorption. For context I live in AK and materials can be limited or cost a fortune to get up here. My options for the most part are GoBoard, keridi, cement board, or Densshield. Thoughts?

So on our bargain basement budget emergency bath build (Not in a basement) shower, I am getting ready to install the NoFlow membrane(Blue lines) . It will extend 12" out the front of the shower curbless opening. I was going to use spray foam for the dam but I am worried about it damaging the NoFlow membrane when it is removed.

My plan to solve that was to make the dam wrap along the very edge of the membrane (yellow highlighting) so any damage is irrelevant. Does that sound like the best plan? Or is there a better damn that will cause less damage.

TIA

Jim

This is the shower floor chapter of the bargain basement budget emergency bath build (Not in a basement)

We have a 36 by 48 neo angle shower on a slab foundation.

Due to cast iron surgery and concrete demo we managed to end up with a recessed shower area to use for a curbless shower.

The tiny bathroom floor will be slab -> synthetic cork -> Prolux membrane with floor heat wires (think K-mart version of Ditra Heat) then ceramic tiles, obviously with thinset in between each layer.

The shower layers are the same except a dry-pack on the recessed slab ramping down from floor level to drain and No Flo membrane before the tile layer.