In stretch-tool there’s this elastic-tape-algorithm. This one sounds great, and does not correct pitch. Use it in sound design all the time, no problem to stretch sounds to 500% or higher.
Concerning presets: It of course would be cool to have this %-setting pre-configured. I have to do this kind of conversion on nearly every project I’m in, but sometimes I have to use different software for conversion, and in PT, for example, you have to do the settings opposite-wise. So a preset would be a good reminder.
I am no overall fan of the solo-musical-mode, you can get huge artifacts on some kind of music with it. Especially quiet music or piano-scores are a problem. Since I of course do all the processing on stems, I ended up duplicating the MX-stem several times, and try different pitch-algos for the different cues. Not that much more work-time, but much better results. Elegic Piano-Scores still remain a problem, in between, I mostly use the elastic-tape-mode for them, even if the material gets pitches for that cue. Better than hearing artifacts, imo. Solo-mode is great on the most other stems.