This is the first time Burt Gummer isn't seen wearing his trademark Atlanta Hawks hat. This time he sports a Chicago Cubs hat.
Michael Gross said that he suggested Burt's hat be changed to a Chicago Cubs one out of allegiance to his own home town's team, and also because there was no real reason that Burt wore an Atlanta Hawks hat, other than his own suggestion as well for the original movie.
Burt's shouting "Looks like you broke into the wrong god damn hangar didn't ya you bastard" is a throwback to his "Looks like you broke into the wrong god damn rec room didn't ya you bastard" comment from the first Tremors movie.
The requisite non-resident special exemption RCMP-5590 form that Burt asks Travis about securing is in fact the proper "Pre-processing Notice to Non-Residents Bringing Firearms into Canada with the Non-Resident Firearm Declaration" form.
Michael Gross was the only person to appear in all six "Tremors" movies. In Tremors (1990), Tremors 2: Aftershocks (1996), Tremors 3: Back to Perfection (2001),Tremors: A Cold Day in Hell (2018) and Tremors 5: Bloodlines (2015), he played Burt Gummer. In Tremors 4: The Legend Begins (2004), he played Hiram Gummer, an ancestor of Burt Gummer. He also played Burt Gummer in the TV show Tremors (2003).