Here is a simpler example in the pic below.
The DAW is playing the source sections, I can also get Sforzando to play them by midi notes (see sfz code). I need the VST to play these sample sections at the ppqpos same as the DAW. The text file has all the source section start/end info, destination ppq, source bpm, pitch change for each track section. So rather than Reaper reading the txt and playing back the sections, the VST will, this way I can play those track section in any DAW using the VST.
Here is a bit on RubberBand:
https://forum.juce.com/t/realtime-rubberband-pitchshifter-working-example/46874
