I was honestly trying to start a discussion about what a mix knob would mean for modulation effects, I wasn't digging my heels in the sand with a "No, we're not doing that." To that end, I believe it is useful if we all know what the Intensity knob is doing on a per algorithm basis. In some cases, yes, it is a wet/dry mixer, but in the case you seem to care the most about, ModFilter, it is not (I never said it was).
In ModFilter the Intensity knob sets the center frequency and Q at which the filter modulation happens around. The Xknob is actually used in stereo mode for spreading the filter sweeping waves up to 180 degrees out of phase, so we can't do a wet/dry mix on the Xknob. But it sounds like what you really need to do is mix in your dry signal with the bandpass filter. This would create a peaking filter of sorts.
We could probably add a peaking filter option to the filter types, and I bet this will get you most of the sound you're looking for.
