These features are engineered before the ground moves. Rock formations require structural support and hidden drainage buried beneath the surface. Infinity edges demand leveling tolerances within fractions of an inch. Swim-up bars need waterproofed cabinetry, recessed plumbing, and materials rated for permanent immersion. Water slides are formed on-site from shotcrete, not shipped in prefabricated.
None of this is improvised. All of it is planned at the design stage, because once the ground moves, these decisions are permanent.