Why does my Blender skeletalmesh have incorrectly scaled physics?

I already read all of that. And tried using UCX_bonename
etc but that seems to be only for static meshes, not skeletal meshes.
I followed this tutorial:
Vehicle Modeling/Rigging Tutorial in Maya for Unreal Engine 4 - YouTube


combined with this one for blender3D

and this is the part that doesn’t work anything like my mesh imported from blender
Unreal Engine 4 Vehicle Tutorial (Blueprint) - YouTube

The imported bones are too small and the “single convex hull” creation fails miserably, creating just one mesh for the main bone, and drawn at 1/50th of the actual car scale, and ignores the bones in the wheels.

I would love to be able to set up the collisions in blender itself, but like I said, the UCX_ UBX_ USP_ seems to be working only with static meshes, not skeletal meshes.