Stretch Samples in OSC 4-6?

Great Synth!
just one thing missing!
Is there a way to stretch the chosen Sample while playing different keys?
Right now it behaves just the old school way - speed up Sample while playing higher and the other way around!
Would be fantastic if you could make it possible, to turn stretching on, o the length of the samples stays the same, all over the range ( or maybe a radius like Izotope Iris).