Maintaining constant altitude above ground

I’m wondering if it is possible for DD to use an existing low-res DEM to determine waypoint elevations that will maintain constant altitude above ground.

Imagine mapping a large ~1-2 km^2 section of a conical volcano with ~30° slope. Even simpler, imagine trying to map a planar surface with 30° slope. As far as I understand, at present I can only enter a fixed altitude above my home point surface elevation. This altitude must be higher than the highest surface elevation I’m trying to map, which means that the altitude above the lower portion of the slope will be very high, with reduced image GSD.

What I want is to maintain ~100 m above ground for the entire slope, to maintain image resolution and stay within regulation. Is this possible, or will it be possible in future versions of the DD app? Thanks.