Hi HSE
OK then let's demystify it.

These .cop files (
Common
OPtions) are a set of settings and include files for each of the 4 compilation targets in the \ObjAsm\Code\Objects\Lib directory.
These are 32A, 32W, 64A and 64W. In each of these subdirs is a different .cop file.
If you are compiling for either of these targets, you
only need to use the files from one of these directories.
The idea of using .cop files was already there in ObjAsm32 (ObjMem32.cop) and I continued to use this concept in the Fusion project. By the way, ObjMem.cop currently also present.
The reason I used full paths in the MakeObject.cmd file I sent you is because it was a sort of quick solution. I could use the standard framework paths as well.
I'll review your changes this weekend when I have a little more time.
Regards, Biterider