I think you'll see that most of the people using bias tires still are on 13 inch wheels and run lighter cars. The bias tires just don't hold up for a race on a car over 2k lbs if your pushing it really hard and running up front.
The 3 EP cars I help are all on radials and have run in the last month. I will be on radials in EP next year for Daytona runoffs. Will be doing testing soon with DOT and EP radials. Will share results openly.