On June 13th, 2020 I repeated Anthony & Will's round of the Bolton Backcountry in unsupported style in 3h58m33s. I don't often choose to run on ski trails but this loop was wicked awesome. My only navigational hiccup was finding the base of the Cotton Brook ski trail where it meets the Cotton Brook Road; after passing it and doubling back, I still couldn't find it so I bushwhacked along the drainage for a couple minutes until I found it. All in all, this appears to have added some distance and time to the effort, in comparison to the original route.
Navigation skills and familiarity with the area are huge bonuses when attempting this route! Don't expect normal footpaths on Woodward and Cotton Brook. Prepare accordingly.