The portability issues of `package-vc-install-from-checkout' are due to issues with symlinks not being portable, which is what that function relied on. None of

The portability issues of `package-vc-install-from-checkout' are due to issues with symlinks not being portable, which is what that function relied on. None of this is related to tree-sitter. That is the function that the combination of :vc and :load-path would use, which just had to be transitively deprecated due to the mistake in `package-vc-install-from-checkout'. Critically `package-vc-install-from-checkout' _does not_ do any retrieval, the checkout of the package had to already exist beforehand, which use-package did not take care of. The function just made sure that package.el would activate the linked directory. User Lisp provides this same functionality. Do not confuse it with the :vc keyword that invokes `package-vc-install', which actually retrieves a checkout of some repository and prepares to do be loaded by package.el. This is the kind of research that I would expect an article like yours to make. It is totally fair to contact the people who worked on this, instead of being smug about it and caricaturing the Emacs maintainers as conservative.