Third times the charm? We shall see.
I really like and recommend those little orange wedges. They work to prevent “lippage” or one tile edge being higher than its neighbor. This is very important for a surface that will need water runoff and also contact with bare feet. If bear feet are in your shower, lippage is not your biggest problem today.
To recap. Lots of decisions made this job much harder than a normal tile floor. Deciding to do it myself added complexity because I have zero experience doing this. The diagonal pattern added complexity. The hidden linear floor drain added complexity. And finally, putting a bathroom where a bedroom used to be added even more complexity. So, there are lots of reasons why this project is dragging on forever.