Yes, but it's not globally recognizable. that's why doi's are standardized through ISO https://www.doi.org/ Internally you could implement a DOI->HASH mapping, but a quilt hash isn't going to help in the reference list of a paper (if you're lucky you can copy'n'paste it. How do you know where to go? What happens if your package organization changes internally and so forth.

This is more than adequate. DOIs are simply redirects. It's up to the data owner to point the DOI at whatever resource contains the data. If a DOI is registered, it can be pointed to the quilt URL.

You can take it a step further and either integrate with a DOI provider or become one yourself and integrate the registration process within your api or create command line tools.