I don't know about that, but I remember doing a rather busy Tower at Aberdeen in the '70s (no Radar then), & looking towards Dyce & downwind right for 35, & seeing two light a/c obviously downwind & very close together, which APP hadn't told me about. I turned to the APP Procedural controller (sitting next to me ) & asked what the hell these two a/c were doing downwind in my circuit without being notified to me.
"Don't worry", he said, "they're separated, one's not above 1000 & the other's not below 1000" !
"Would you like to think that one through, again, xxx", I asked. But, I don't think that he got it.