The Ribble Way on the opposite side of the valley runs near to long lengths of similar crags. As far as I know, these have not been developed. They are situated along the track between Birkwith Cave and Sell Gill Holes. This is not CRoW land so permission may be needed.

I looked at the small edge at High Birkwith years back but was pretty disappointed, this crag is good though. I'm sure it was developed years ago but I was unable to get any information for it so I just climbed the more obvious lines. You're probably right that permission is needed, not sure where from though!