Will sand stay in place under liner with custom design

I want to build a pool that will use the earth as sidewalls and eliminate the need for AGP or costly cement walls. My thought was to incorporate some details from a natural pool design, elements of adding a deep end from AGP manufacturers. This would require that a custom liner to be built. I am concerned that without the traditional sunken AGP with 4ft sidewalls of water weight on the floor that the sand will shift in the shallow depths. any thoughts?

* Beach entry with a 1:3 slope ratio as suggested by many natural pool designers.
* Deep end slop of a 1:1 slope that I see from DoughBoy installation guide
* I want to put compacted mason sand under the liner
* Side walls are 1ft, which is a deck fascia board with overlap liner
* I am concerned with the little water weight in the shallow end, 1ft-3ft, there won't be enough to keep the sand in place