I have recently had issues with antialisaing when using a commercial renderfarm and 1.5. The support at the farm told med to run the images for 100 passes despite being clear at a lower number, and it helped on a previous project, but not on this one.
The renders was set to highlight clamping 8.
What render farm was that? We can try contacting them. Do you know if they provide the files which are opened on their side? Maybe we could take a look at filtering settings which were used in their files?
Sorry for the late reply. It’s at Rebus - works fantastic in general, apart from this one issue. Let me just contact them once more and see what they can give access to.