I think it depends somewhat on what the proportions you're talking about are. Ben Tilly's slide seems to be saying that changing already enrolled users from A t

I think it depends somewhat on what the proportions you're talking about are. Ben Tilly's slide seems to be saying that changing already enrolled users from A to B is bad, clearly. I don't think changing the filtering rate on new users would be bad, but I haven't looked at the mechanics in a while.