Thanks, man, I don't know why I did not find that outfit in my searches.
And since they are a Canadian business I know they are the ones that supplied the printer maker.
Based on reading their docs ( a little) I think my original supposition might be correct,
that (in this implementation) the closed-loop motors are a drop-in upgrade and the 12 pin connectors are just being used as the easiest way to interface with them. I had hoped that a photo would let me see if only some of the traces linked up to the connector interface cards but I can't see (photo below).
Since this started as a Kickstarter campaign I'm pretty sure they were doing things as cheaply as possible.
And buying premade cabling and some motherboard connectors would be the cheapest way to go vs. making up custom cables that only connected the pins that were actually used.
As I mentioned prior, the ability to add a closed-loop daughter card to the back of a stepper motor and then update a few parameters and have it be driven by the existing motherboard leads me to believe that the added capability is in the daughtercard board and in the case of the Cool Muscle motor it's just internal.
And they did not have different firmware files for whether you had the original stepper motors or the CM.
I think any updating/tweaking was only done through the terminal.
But I will check with the Canadian distributor to see what they say.
Thanks again for the very useful link.
M./