I understand your reasoning as to why a “fatter” unison using detune is not available on the Poly61 using ModyPoly:
. . . due to the Poly-61 beeing DCO based there is no detuning between the six voices . . . Even though it does not make sense to use 2 voice and 3 voice modes with a DCO based synthesizer (you just get less voices, but not the advantage of a ‘fatter’ sound), the extended unison mode offered by the ModyPoly might be interesting for some users for its emulation of classic monophonic synthesizers.
Perhaps I misunderstand something, but it seems to me that you’ve overcome this DCO unison detune issue with the Juno66 mod, and so I wonder if you think it would be possible in future to do the same for the ModyPoly and the Poly61?