The non-backwards compatibility of VESC-Tool has been very frustrating because it seems to require a firmware update if I don't have an old VT binary or APK handy. And as the old embedded c++ saying goes:
If it aint broke, dont fix it.
Each firmware upgrade carries with it a non-negligible risk of bricking during upload, wrong detection, changes to the throttle in the app settings, c++ bugs, and generally requires a proper shakedown test and validation. In some cases some dis-assembly is required, need to go to the workbench, etc: its not nothing.
Working firmware that is properly configured with the right settings is a rare and amazing beast. So once I have such a thing, I do not want to mess with it. I don't care how much better the new firmware is, or how much time was spent on it. Messing with a working configuration is not to be done on a whim, and it's not to be done on a schedule dictated by a group with no connection to a particular vehicle design.
It's important to understand that electric vehicles are now mainstream and are used in commutes and daily life. They go decently fast and share streets with automotive traffic. If there is a firmware issue, it could cause serious injury or death. To update VESC-Tool and force everyone who doesn't have the old APK or VT binary to assume the risk inherent in any new firmware is... not good.
VESC-Tool needs to be backwards compatible, or make it able to select older firmware versions from VESC-Tool so users can choose to update when they have time for a shakedown test and settings check, or when they have seen the more daring users operating safely.
Yes I know there are VT clones that do this, but this is something VESC Project should take seriously as a group.