Hi. I see from the org-mode 9.0 changelog
<https://orgmode.org/Changes_old.html> that the "org-completion-use-ido"
option was removed:

> *Remove all options related to ido or iswitchb*
> This includes org-completion-use-iswitchb and org-completion-use-ido.
> Instead Org uses regular functions, e.g., completion-read so as to let
> those libraries operate.


However, I'm unclear from the changelog and I haven't found any other
documentation about how to restore the functionality that this option used
to enable. I have tried ido-completing-read-plus/ido-ubiquitous
<https://github.com/DarwinAwardWinner/ido-completing-read-plus>, but that
is overkill because it tries to enable ido everywhere, but I just want to
re-enable ido for org-mode completion (mainly refile). I also run into the
same problem if I try to set the completing read function to the one from
ido globally.

What is the best way to restore the functionality of the now removed
"org-completion-use-ido" option?