Well, if you're working with oscillators, it's dead-bang simple to mock-up an abstraction that substitutes for the mtof object and kicks out the particular frequencies for the scale *you're* interested in. I've done that for ages.
This is my first Max 4 Live device that I didn't copy from a tutorial. It allows you to set your concert pitch in Hz, then calculates and applies the appropriate amount of pitchbend... and still allows you to use the pitch wheel in performance. The microtuner I found on the M4L site asks you to type in a cents value and disables the pitch wheel... so I hope this is an improvement.
MR_ZLATKO, nice work with your zb.detune effect. I'm very interested in your polyphonic workaround. I've been trying to figure out a way to polyphonically retune MIDI instruments in Live with the same pitch bend method, but Lives insistence on sending all MIDI out of channel 1 is vexing me. How does your work?