Forgive me, this is really neither here nor there...

RRX: Can't you do most of that using hash tables? They'd be very quick (they're all stored in memory) and it already doesn't require opening a window.

You wouldn't be able to use /filter but there are many options that become available when using hash tables. I'd also bet that it would be as fast, if not faster, than using /filter. I have no proof backing that up, but it'd be easy enough to test.