Hipass/Lowpass slope controling

It would be great if there's the possibility of controling the slope (-6db;-12db;-18db;-24db/octave) in the eq or wah pass section.

For exemple, in the case of two guitarists in a band, the first adjust the high pass at 80Khz with -18db/octave slope, and the second adjust at 100 Hz with -6db octave.
It would allow a better complementarity and clarity for the two guitars.

There would be many other exemples. It's a very good tool for mixing.