If you're reading this article it means you're concerned about 65mm spindles installed onto Onefinity's with the default 65mm mount.  
We've never found this to be a serious problem if you've installed the spindle properly.

Below are a few pictures of my own Onefinity with our 65mm air-cooled spindle installed.

The key i've found is during installation, lower the Z all the way, slip the motor into the mount but do not tighten.  Raise the Z all the way up while holding the motor allowing the mount to slip up over the spindle body.  Once the mount is all the way up, lift the spindle up until it bumps the bottom of the Z motor.  At this point tighten the mount to secure the motor into place.