That looks like a difficult machining task to put that dutch pin between hardened steel and aluminum
Any motors do better than others? I believe the Maytech sealed motors have an extra bearing there, but not much else to mitigate these issues?
I saw the pics of the larger 6380s with the 4 bolts, heres a pic @torqueboards sent to me.
The windows are not machined out on all 4 sides, making this very difficult to do on the 6355 cans