A little late, you probably already have a solution but I wanted to chime in. You can not raise your custom collision limit as there is a hard lid on it. The main reasons being flexibility and performance. Having that many collision channels is pretty cost intensive. Instead you should look at other gameplay mechanics that will help you achieve the same goal and is more performant than collisions.
Example, use gameplay tags. Keep all your vehicles as vehicle objects and when they create a hit or overlap event, run a function that checks your tags for the things you need such as Vehicle.Crush and Vehicle.Avoid… You can create teams with tags as well, assign a team tag to a vehicle at start and when they collide if they have the similar Vehicle.Team.Blue tag then they avoid but if it’s Vehicle.Team.Red and it has Vehicle.Crush tag then do your crushing.
Your Crush Level should be an attribute on your vehicle and applied whenever crushing another vehicle. The vehicle being crushed should have an attribute called Crushed Amount and decremented by the Crush Level. Think of this like a Health attribute that gets deducted every time it is shot.
Tags are super cheap to use and very flexible. I would look into something like this long before I thought of adding so many collisions. Collisions will kill your performance rapidly. Good luck to you!