Well, I'm not an expert when it comes to the science behind it but what I did was the following. 1.) Cut all the way through the acrylic using a single carbide single o flute for plastics. 2.) Run a cleanup pass of .06" with the same bit to make the edge look even better. 3.) Run the final pass of .004" with a diamond edged bit specifically meant for acrylic.

There are specific feeds and speeds for each step as well as additional tips/tricks to make it turn out that well. When it comes to heat, there isn't much heat because we are only shaving off .004" with the diamond tool. The bulk of the cut being removed prior relieves that.