you will not get .020 deformation with a phenolic tip.
All that aside, I use a flat break tip , except it has 1/8 inch rad on the outer corners, so effectively there is only a 1/4 inch or so of flat area.Never had one fail yet, but I have not been in the buisness 20 uears either.
I just hit center Cb, If I wanted some english, then a radius on the tip would be a must.Then I use a superpro tip with about the rad of a 1/4 dollar.
Neil