Quoting Samuel Thibault <sthibault@debian.org>:
What kind of relaxation could we introduce without damaging freeness?
And damaging quality. If a program uses some JS libraries without any sources easily available, I cannot really promote this software. Neither in Debian nor outside. This is just bad practice.
Or we could try to embrace the multiple-library-versions-in-the-same-root issue like distributions such as NixOS and Guix do. I.e. standardize alternative places where alternative versions of libraries can be installed (by installing package whose name contain the major/minor version so it fits nicely into the dpkg model, and not the release version so that upgrades are still possible), and the corresponding environment variables be used to point those complex software at these dependencies.
This sounds good, at least for JavaScript libraries and esp. the Node "ecosystem" (a.k.a. toxic waste dump). Cheers