Because addons may have multiple folders which are manipulated in the packaging process using .pkgmeta - eg moving module folders etc, it would be useful to support non CF addons to be installed by providing their url. This could also be handy for working copies of older addons which are being maintained but have not yet been transferred on curseforge, a common problem when author's disappear off the radar.
This process should respect pkgmeta by doing any necessary moves/dep. installs etc, as well as allow users to keep addon up to date using tags as releases or commit sha's as alpha/beta