break up the collision into multiple boxes
But this would then be the equivalent of complex collision, you’d collide against every face 
- just like Complex… but worse since this actually wastes triangles as there’s a bunch we cannot see that will never be utilised. For every 8 faces, you never utilise 4 unless you’re using different pieces for start / mid / end. Or merge them. Or later on turn that into actual procedural mesh which would be most optimal here.
And it still cannot make sloped terrain. Besides, note:
the ball is you’d easily see that the ball is either hovering or clipping through the ground. My ground tiles range from 2 triangles to around 150 triangles on more complex shapes like the hole
Judging by the original post, OP already has pre-set pieces so that probably could never work for them anyway.
@HybridPosts If you ever run into performance issue or start optimising, do look into UCX collision. It would need to be done outside the editor and then imported, it allows you to hand craft much more complex and tightly matching custom collider shapes that can be used as Simple. It’s the best of both worlds but laborious.
If your tiles are 150tri, it’s probably irrelevant. And very relevant if we’re talking high poly.