I could be wrong, but....

I'm looking at the "X-Terra Pro", and the fact that it is compatible with the Equinox coils,
and it is screaming "stripped down Equinox"! to me. Since the Equinox coils obviously work
between 4 & 40KHz, and this new thingy looks just like a NOX, I'm pretty sure all they did
was take an Equinox and program it to work on a few specific frequencies. They removed
the SMF part in programming.

Chip makers do it all the time. Take the full blown chip and only allow it to work in
limited modes. Whole lot cheaper than designing a different chip.

If the Nox coils work on this new thing, I'm sure the new things coils will work on a NOX.
They maybe label them differently, that's all.

Might be good for people's budget that doesn't allow for a NOX 800, but I'd save a little
more and get the real thing!