Found some info on the vst storage method of its parameters in
https://forum.cockos.com/showthread.php?t=45198. It is different for each vst, and encoded in “base64”. It is called “opaque” and there’s a good reason for that name ;-)
I created several projects with a single track, a single plugin (reatune) and one or 2 corrections only. I was able to change the start and end note of the correction but that was a lot of bad guessing, for pretty random results. Very mitigated results for time change. I am semi-confident that I can create a small utility to move or copy corrections, but any help would be appreciated. I’ll keep you posted!