There doesn't seem to be a way to strip out the `#+title` from an
`#+include`d org file. As a result, for complex org documents, if you end
up `#+include`ing multiple org files that have `#+title`s, it ends up
appending them all, which can often not be what you want, which is true in
my case.

There's this solution I found, but it strips out the title entirely, rather
than controlling which `#+title`s get exported, such as only the title of
the root doc:
https://emacs.stackexchange.com/questions/18420/unwanted-concatenation-of-multiple-title-and-author-when-using-include