In using the 'Controversial' sorting option for my All feed, I found that it was consistently only able to load a limited number of posts before erroring out.
Edit: After testing in Safari via the regular Lemmy client, the same behavior occurring seems to indicate that it's a bug with Lemmy itself, rather than Arctic specifically.
Edit: Confirmed with the Lemmy developers that it had indeed been a bug in the backend, but has already been resolved in a development version of the software testable on voyager.lemmy.ml.