When using COGO tools there should be a parameter for relative elevation, so that there is a distinction between a null value and a zero-relative value; with the option to show relative elevation of the live location or any selected point. This is also known as azimuth and over a few miles distance can result in a significant amount of error in measurement if not considered. There should also be a relative bearing from a basis of line between two points, as "true north" is error-prone in a survey. When COGO callouts are legal descriptions referring to benchmarks on some rocks at mountain peaks referenced by telescopes in the 1800's, and all you know is what was claimed to be a basis of bearing between two control points that you do find monuments for; to verify that these are sensible you can shoot points for those benchmarks and calculate if the callouts make sense or have been disturbed/offset. In USA the Public Land Survey System uses, varying by state law, easting and northing with a basis of bearing referenced to well known benchmarks and less commonly anything to do with true north or magnetic north. Disclaimer: I am not a professional surveyor my use case is to plan a farm and ranch for myself; over a distance of a few miles being off by a foot or two is only reliable if it is repeatable and QField / QGIS are missing the ability to do callouts reliably.