If a GPS coordinate is used to describe a location, every effort should be made to establish a permanent mark, whether a spike with whiskers, a ΒΌ" rebar, or something else. Then, when the GPS operator gets in the very-near vicinity, they should be able to locate that marker.
I know it is not always possible, but lacking a viable landmark, GPS coordinates in conjunction with other descriptions and placed-markers sometimes have to do.
It should be rare that a Start or Finish has to be so remote that there are no landmarks to reference. Split locations can be remote very often, and I have used the combination of vague descriptors and GPS coordinates more than I would like. But, if a Start or Finish is in a gathering place, isn't there normally something there to use as a reference?
Just my thoughts.