Besides time and pitch it would be great to have a classic tape mode for time stretching as well (compare Ableton Live's Re-Pitch, Bitwig's Repitch or Cubase's Tape mode).
Explanation:
Re-Pitch Mode (taken from the Live manual)
"In Re-Pitch Mode, Live doesn’t really time-stretch or compress the music; instead, it adjusts the playback rate to create the desired amount of stretching. In other words, to speed up playback by a factor of 2, it’s transposed up an octave. This is like the “DJ stretching method“ of using variable-speed turntables to sync two records, or what happens to samples in traditional samplers when they’re transposed."
Tape Mode (taken from the Cubase manual):
"Locks the pitch shift to the time stretch as if playing back a tape with varying speed. If you stretch the audio material, the pitch decreases automatically. This variant has no effect if you use it with event transpose or the transpose track."
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As Studio One 3 uses zplane's Elastique algorithms as well I hope the addition of the "Tape" mode / algorithm shouldn't be that complicated.