The idea is to go all the way to Ps121, so logically if we start from the 4x4 parking near Roxy1 then we wont be finding the "Nature reserve" caches lower down, maybe try and squeeze in the new Helderberg lookout while returning on the contour path.
And if we start from the parking within the Reserve then we wont find Roxy1 and treasure chest, theres just not enough time in one day.