How do you test changes to a blueprint without publishing?

The reason I don't want to publish a blueprint is because, I might have broken something and I would hate to push that churn to my users while I figure what I'm doing.

Ideally, (I think?)

I would like this supported: `ember-cli-update init -b ./path-to-blueprint-repo`

But, if there is a way to test locally without doing relative paths or without publish via some node utilities, that'd be cool, too