The default Undo and Redo Macros that are installed with 3DxWareMac_v10-6-0_r2876 are non-functional as intended. I don't know if it's a keyboard localization thing, a keyboard re-mapping thing, a 0-indexed range thing, or what, but I honestly don't expect these sorts of issues when throwing $400 at an input device. That is most certainly a premium price and should net a premium product, hardware/firmware/software included. Sorry to be direct, but there it is.
As released:
Undo: ⌘ y
Redo: ⌘⇧ y
Should be:
Undo: ⌘ z
Redo: ⌘⇧ z
Obviously, I've sorted it for myself in the meantime, but it might be nice for the next new owners to avoid the issue...
I would have reported this to technical support, but I'm unable to create an account making that avenue impossible...

...along with registering my purchase...
