Hi,
Thanks for sharing. (And thanks for your diligence with the code in our medical devices!!!)
You may be interested in the “regulatory” report that’s available starting in Enterprise Edition($$) if you’re not already using it.
And in the meantime, yes, cranking those housekeeping settings up is probably your best bet. Either that, or putting an event on every analysis, although at some point even snapshots with events are cleaned out.
The events you can control are version change (sonar.projectVersion) and custom events, which are typically added through the UI, although that could be scripted. This guide may be helpful for that.
And BTW,
Turning off housekeeping will keep every change. At least for a while. (Maybe storing regular DB backups is the answer here?)
But it’s on you if your DB bloats. 
HTH,
Ann