How do we know when bug fixes have been issued to QGC stable version and we should redownload the stable version?
Like Lorenz said there is no automatic way for that. If a bug gets fixed, it will show up in whatever Stable goes out on a date after the bug makes it into a Daily build. The release of a new Stable builds is announced on both the gitter channel and the google group.
Thanks for that info Don. May I suggest the bug fixes to stable builds be announced on the support forum as well?