Are you waterproofing before or after screed?
Personally, I get the plumbing sorted first including the puddle flange, then have the tiler screed and then waterproof on top of screed and into puddle flanges. I use waterproofing tape on all internal corners rather than just bond breaking with silicone.
Waterproof all the walls in the shower area to 2.0m or the top of tiles. Waterproof all the floors and up the walls at least 100mm outside the shower. Basically tank the entire floor. Waterproofing is critical so take the time and effort to get it right.
I will be waterproofing the bare concrete floor and then top of the screed to sandwich them in, not sure if that's an overkill.