I am passionate about coding. I use autocad's lisp and vba, solidwork API, to compile code to improve my work efficiency.
For your project, you can export GPS Units data to a data file.
I can code in AUTOCAD LISP or VBA or Python, read this data file, and insert a block into the DWG document based on GPS coordinates and elevation.
Block insertion point, attribute is consistent with GPS coordinates, elevation
I can also program the code to remove all previously inserted blocks.
I recommend using AUTOCAD VBA to complete your project, this is the easiest way