Ben Hunsberger, who played the unmasked Bhen-Jah-Man during Chapter IV, is the real-life Ben Hunsberger that the film was based on. He couldn't play Ben due to scheduling conflicts, so Tristan Noller took the role.
Mason Vietti actually really despised the taste of La Croix when filming began. However, having to drink it so often, he ended up developing Stockholm syndrome and took a liking to the sparkling beverage.
The story that Emerson tells Donegan about the origin of the term 'bonzos' is actually a true story. Emerson Welsh's real-life grandpa refers to him as 'bonzo'