Well, I am not a good programmer, but couldn't we then have a macro which "pre-processes" the CNC code before MACH executes it?
So this could put those special M codes right in place... But as far as I understand this would be in fact a post-post-processor
If it is a seaparte macro, then at least we wouldn't have to write it for each CAM application individually, but rather run it for the post-processed G-code set, and then load into MACH3
So unless Artsoft makes this auto-tuning-switching a built-in feature of MACH this could be a useable solution, no? And if we use standard G-code programs, well, nothing would happen, it would run as earlier...