Traditional tile shower pan has multiple layers:

tiles (top most layer)
mud job, also sloped
waterproof membrane connected to subdrain
a presloped floor (bottom most layer)

I read that a new technique is

tiles (top most layer)
bondable waterproof membrane
mud job, sloped (bottom most layer)

The purported advantage of the new method is less work, and the mortar bed
do not get soaked in water constantly.

Setting tiles on a membrane sounds kind of scary. Is it proven to work well?