I don’t know about that bike specifically but some have shocks that you can lock. The guy in the video does use the bike off-rail when he encounters obstacles and to get to/from the track. There’s another video where he goes into some detail about the design and manufacture of the bike as well as the drone video process. He is a true “maker”. He did mention that the bike is set up with a slight inward lean.
We did one of their excursions about 2 months ago. It was an old abandoned rail line that some touristy-leaf peeping style railroad came in & was fixing up all the tracks to standards (RR are federally regulated) but went belly up before they began operations. RevRail saw these nicely fixed up rails on an otherwise unused, relatively flat route along the river; didn’t even have a street crossing to worry about (though one of their other routes does have a crossing; our guide knew about it but didn’t know details as he doesn’t work that route). RevRail, using custom made, human powered, pedal carts does not need to adhere to all of the federal RR regulations. However, there was some obvious signs that they were doing maintenance on the route in terms of a couple chainsawed trees that had fallen over the tracks.
Their wheels have about ½" of rubber on the outside to make them quieter & more comfortable. You felt when you went over the seam between two pieces of rail but it was a minor bump, not like hitting a pothole in your car.
The route we rode has a road crossing and they had a worker there with a flag. It was a lightly used road and we never saw any traffic. On the way back the worker wasn’t there - we just slowed down and checked both ways.