Thing there is, with the possible exception of Beanley 1 the Beanley stuff is associated more with The Ringses camp. If you look at the level of complexity, it gets more complex the further west you get, with Beanley 1 being more complex than the others. Those on the eastern edge of the moor are slightly iffy cups. Dripping thick with monster bracken too.
Anyway, what I'm getting at is that there is a vague pattern to suggest that the closer you get to the more substantial outcrop by the Plantation fort, the more complex the rock art. Given that many of the other fancy panels in that bit of Nbland are usually on west facing outcrop near freaky karst features in the rock, I reckon there's a good chance that the plantation fort could have had it's own more complicated RA. Add in the cist, and the more complex motifs on the Beanley Moor cist cover (The fancy one in Alnwick castle's Postern Tower museum). Problem being it might well be that any Beanley plantation RA probably either got itself quarried away or buried under a couple of feet of pine needles.
Then there's the RA gap between Beanley and Hunterheugh, in the form of Kimmer Crags, which lie above a prehistoric cairnfield and a nice wee lough, both good pointers to the (onetime?) prsence of some RA.
Hey, I can live in hope ;)