Jeff King [off-list ref] writes:
However, as I said elsewhere, I'm not convinced this feature is all that
helpful for in-repository .gitignore files, and I think it does
introduce compatibility complications. People with older git will not
respect your .gitignore.d files. Whereas $GIT_DIR/info is purely a local
matter.
As I do not see the point of making in-tree .gitignore to a forest
of .gitignore.d/ at all, compatibility complications is not worth
even thinking about, I would have to say.
Thanks.