I think its time to reopen the idea of requiring that _debian/copyright_ use SPDX tags when the license texts are an exact match. I think SPDX has progressed nicely, and has gone through a number of revisions to address the concerns of Debian and others. This then will greatly improve the machine readability of our software collection. That would in turn make it easy to generate an API of DFSG-free licenses that others can consume, including SPDX:
https://github.com/spdx/license-list-XML/issues/876
