Have you ever looked into using G52 to make the same offsets work on two different parts?
You set all your Tool Offsets to a reference point that is higher than the highest part and set your Work Zero to a reference point somewhere on the table.
Then for the first part you have a command G52 Xx' Yy' Zz' where the x', y' and z' are the coordinates for the X, Y, and Z zero points on the part with reference to the Work Zero and the position you used for the Tool Offsets.
For the second part the command is G52 Xx'' Yy'' Zz'' and the x'', y'' and z'' values are the coordinates for the second part.
Once things are calibrated and the values are in the program you do not need to change or overwrite anything.
An open mind is a virtue...so long as all the common sense has not leaked out.