I'm very excited about this. I'd love to hear some audio demos of what its linear FM patches sound like.
Programming FM sounds is always challenging and is heavily dependent on minute changes in the amount of modulation, whether it's the amount modulating oscillators affect the carriers, the amount the envelopes affect either, or how much velocity affects things like the amount the modulator modulates the carrier or the decay rate of the modulator's envelope.
I feel that the importance of envelopes is often discounted when it comes to Lin. FM. One of my favorite features of the DX7 is that instead of a common ADSR envelope, it had independent amounts for each stage of the envelope as well as settings for the rates at which it would reach the peak amount of each stage.
At any rate, I'm genuinely excited about the possibilities of linear FM on this beast!! I can't wait to hear it in the context of some music.