Collisions inside the blueprint

Hi guys/ettes, I’m just a litle curious of how to solve this issue, all and any help are greatly appreciated.
First you take a preimported mesh, go into it’s properties to create a specialized collision mask for that mesh, and then create a blueprint for that item.
Now if you use the meshes current size and rotation everything is fine and dandy, but what if you want to changethe size etc.? You need a scene or a collision box to be the root directory of the blueprint, and that will either take over the collision or ignore it all together.
How can keep the collition mask you created in the meshes properties without making another mesh for that size? Can you create a specialized collision and use that as a root instead? I’m sure there is a good sollution to this, but I cant understand what it isxD