Peter Debruge Chief Film Critic How long does a documentary need to be? Frederick Wiseman frequently goes long, and Oscar-winning “OJ: Made in America” ran nearly eight hours. Lately, with “Bill Russell: Legend” and “Boom! Boom! The World vs. Boris Becker,” streamers have embraced the so-called “two-part documentary” — a fancy term for what used to be called a miniseries. So, while there are no limits on how much longer docs can get, it’s refreshing to see a compelling subject covered in 40 minutes or less, and doubly rewarding to realize that four of the five packaged in ShortsTV’s “2023 Oscar Nominated Short Films: Documentary” found audiences on their own merits, even without theatrical distribution.