Gerry,
I got a definite maybe response from Robert:
"I just had to go back in my code to double check but Meshcam should be
outputting absolute IJ. I may have to do some more testing to make sure
I'm not reading old code wrong but that's what it looks like to me.
For what it's worth, I use Mach3 on a Tormach and it works as-is.
That being said, your machine may have a different default configuration
so if it works, keep it."
-Robert