Licensee reports that occluded vertices are picked in mesh paint when multiple meshes are selected.
Since we use line tracing + math to determine the target vertex in mesh paint mode, rather than hit proxies, the problem is probably something to do with the complex collision not being set on the foreground (occluding) object. Not immediately clear how we would solve this.
Video in the UDN ticket.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-169508 in the post.