Tonight I finished the front foot / ankle mount and gave R2 a good test drive around the neighborhood. This ankle mount works GREAT and it's solid as can be as well as very level. So technically R2 is back in service.
One thing I like about this new design is only 2 small bolts hold the assembly together with no shims or other things to complicate the design. Less to go wrong. Functionally it couldn't get any better in my book. Oh yeah, a softer lighter tire replaced that massive thing I had before.