OK, this is a bit of a weird one. Let's say in thread 1000, user A posts post 1, user B post 2, and user C post 3 in that thread. User A then replies to B and C, multi-quoting both posts in the reply. What then happens is user B (me) gets two quote notifications for the same post in the same thread. I'd assume that user C also gets two notifications. Clearly there should only be one notice to both users.