I know you told me I can get around this by using two provider tubes, one with the item on the blacklist, and another one on whitelist to set the limit of how much to keep to a different number than the one set globally, but this seems like something that would be a useful feature to have on a provider tube, and even something that I think should be the default mode for it, because the way the gui is designed, it feels like it should be able to do this.

So a keep mode that ignores white/blacklist effectively

Yes, exactly.