Are there any synthesizers or virtual instruments that bend the fundamental+harmonics with the right stretch, and separarely from the formants/inharmonics for a

Are there any synthesizers or virtual instruments that bend the fundamental+harmonics with the right stretch, and separarely from the formants/inharmonics for a more realistic bend? When I bend a guitar or violin (or piano) on my Korg workstation it sounds like a nasty digital resampling bend, and very unnatural.