I have seen the same thing on my EZIO6I when I left AN2 float. Not sure about connecting the single control across both ANx inputs. Seems like it should work from the EZIO8SA perspective but not sure how the current sensor output would be affected. The spec on the current sensor does say the output is overload protected so it should be safe to try it. I think you can connect GND on the EZIO8SA to the AN2 Input, putting AN2 in a powered ON forever. That is what I did with my EZIO6I. Was afraid of putting the 12V to AN2, even through a pull-up because of the low voltage range of the ANx Inputs. The EZIO2X4s are easier to work with in this area because they provide a 5V source that the pull-up resisters can be connected to. The opto-isolated Inputs have the pull-up resister built into them. They can’t build the pull-up resister into the ANx Inputs because that would prevent them from being used in Analog mode.
EDIT: went back through some of the older forum topics and they make the same suggestion regarding grounding the unused ANx inputs so they do not float and cause random state changes.