All the contortionist vampires were hired performers from live shows like Cirque du Soleil. This was a way to not only show a different type of vampire, but provide jobs for performers who were out of work due to the Covid-19 pandemic.
When Bud (Jamie Foxx) and Big John (Snoop Dogg) enter the Hunters Union, there is a portrait of Abraham Lincoln and two axes on the wall, a nod to the Timur Bekmambetov film Abraham Lincoln: Vampire Hunter (2012).
When Big John (Snoop Dogg) scans his thumb at the elevator, the machine displays his union rank and full name on-screen; "Venator 1st Class: Eliott, John Dante". Venator in Latin means "hunter".
The vehicles of the hunters and "good guys" all have license plates referencing Bible verses.
When Bud and Big John walk into the union, a bottle labeled "BSB" can be seen. It's Brown Sugar Bourbon, a brand that Jamie Foxx owns.