As counterpart to the velocity tracker meta device, I suggest a “Note Tracker Meta Device”, that reads the note number from a frequency table.
You can do for example note dependent filtering with it. Static filters doesn’t make so much sense on melodic instruments if you want to change the character of the sound with a additional filter.
Ok the only problem is now, if I use the key tracker device to control a frequency of an eq band, say EQ5, the result will produce crackles, as already reported here.
Try it by yourself, plugin an eq5 and move the frequency of one band a lot. It will crackle.
We’re already aware of this and will try to look into it.
In the meantime, you should simply use a Filter instead, since they are much better suited to being automated in this way. In the EQ example song you posted in the other thread, you could use a highpass filter instead to achieve the same result, for example.