I’d really like to be able to bracket filter sounds at the individual send-slot level.
Just like the HPF and LPF in the Pre section of each channel, except individually available on each send slot. Alternatively, a single insert slot for each send so that an EQ (or anything else if you really want — a compressor can be handy sometimes) may be used in this way on a per-send basis.
That way, I can route, say, vox, guitars and drums to the same Send FX instance of a reverb or delay, and decide which bits of the spectrum of each source are sent to the effect — but without having to create a dedicated FX send for each one just to filter it, before sending the filtered version to the final effect.