Like I said, Mach4 Industrial is supposed to have full Fanuc B. I can't tell you what the current state of development is, though. I have a copy installed here, but don't see any documentation covering it.

I would say that it's highly unlikely that you'll ever see it on any other inexpensive controls, as the percentage of users that need/want is would be really small.
And the macro scripting in some of these controls is quite powerful, allowing you to do a lot of things.

Documentation on the Acorn is rather sparse, but looking at the docs on the website, in looks like you need to go to their top of the line controls to get the full Macro B.
The centroid manual that lists all of the variables says it's for the M39 and M400, which are over $11,000