What are your views on producing separate FRA’s for individual cluster flats in the same building? 
One FRA for the whole building? Or separate ones for the cluster flats? I have had differing requests from different clients on this. Thanks  

As each cluster and other common areas are usually under the control of the same client I do it as one - never had any problems.
 

If a whole cluster is under different ownership (rather than the leasehold of individual bedrooms which is a common model, all shared space retained by the freeholder) then it would be different.