I’m not sure this is necessary and I looked through the Reachview docs and couldn’t find where you would even do this? According to this post Ground Datum Use - #21 by jmiranda
“Generally speaking network are adjusted to certain datum, but they all broadcast WGS84 (Lat, Lon, Ellipsoidal Height.In other words, the network receivers track the same information from the satellites than your Emlid Reach does. It is the software that takes care of transformations.”
My photogrammetry software easily converts to any coordinate projection (EPSG #) I choose. So wouldn’t I just survey the ground control in WGS84 (which is what the drone uses), process it, and then if I wanted the resulting output files in a different coordinate system just choose that on the export? If I wanted NAVD88 heights, I think I still would need to find a software tool that will do that conversion for me before I input the ground control coordinates into the processing software.