Thanks Gorp for this - yes - I now see my second sentence was a bit ambiguous I should have more precisely stated that ’With the standard stock ARC PRO the signal polarities of lane 1 and lane 2 are reversed with respect to each other.’ Does that help with consistency and interpretation of my post?
Also I agree that my so called ‘Option C‘ is more complex to implement than slot forum simple soldering mod, however Option C enables rapid switching from full digital capability to full analog capability simply by swapping out the two modified track parts with two standard parts. To achieve the same effect with the slot forum mod would, as proposed within the post, require an additional switch and... perhaps some cutting of the brand new ARC PRO enclosure to make the additional switch accessible. Taking this into account the effort is probably reasonably similar for those users who need both full digital and full analog capabilities.
Thanks again Gorp for spotting the ambiguity in my second sentence - much appreciated!