Having it as a rake task in the plugin sounds smart to me.
I’ve signed the CDCK CLA so any copyright interest on my part in the resulting work won’t get in the way, and it can be put under the same license as the plugin itself.
Also I could imagine that I got something wrong; if you find anything wrong with it, I’d love to know about it because I plan to run that script on my own site sometime in the next few weeks. 
On a larger scale, if you find this framework useful for your own work supporting Discourse installations but would like more error handling, I’d take PRs. I merely want to make sure that any PR to it is from someone who has signed the CLA and agrees that any useful pieces of it can be incorporated into official Discourse, which I know is true for you…