Unit Gradient Lower Boundary Condition for UZ

I would like to simulate a deep water table without explicitly including a deep vadose zone in order to limit computational time.

In other software, I usually do this with a unit gradient lower boundary condition.

Is there any way to do this in MIKE SHE, or any other way to simulate a deep water table without actually including computational nodes between my depth of interest and the deep water table?

Thanks,

If I understand you correctly, you don't want to focus on the processes of the vadose zone, you have a high depth to phreatic surface (long distance between topography and groundwater table) and therefore want to reduce the computational effort for the UZ module:
1. option: apply the Gravity Flow for UZ (doesn't consider capillary rise) and make big numerical parameters for the solver, then it will run quickly
2. option: even faster, use the very simple 2-Layer UZ approach

Since the strength of MIKE SHE is the focus on surface-near hydrological processes, there is no simpler approach, like a gradient boundary condition.