I run into this problem often because I do hip-hop and R&B and a lot of these beats they use have samples in them that are detuned and the sample makes up the majority of the musical composition. Today I did a song tuned in 450.3hz. Unfortunately it makes using Vari-Audio a lot more difficult since the notes snap to 440hz notes (unless you hold shift).
Sometimes I detune the beat back down to 440hz just to make everything easier, but that leaves behind unwanted artifacts.
I guess we need to make a feature request. The “Chord Track” needs to have a frequency setting.