High ambient temperatures and hard track surfaces offer little traction for your dirt late model. If your car is balanced and you want to add more overall right rear grip, this groove and sipe pattern could be a great place to start. As always, monitor your tire temperatures and wear, then adjust accordingly.
As the track's surface cleans off and develops the black/blue slick groove, the lap times start to fall off. The tire needs more flexibility to maintain compliance and more edges to grip the surface. When you cut your right rear tire in an aggressive pattern, it is up to the driver not to slide the car too much. Sliding the car will abuse the edges and lead to poor performance.
Driver and crew communication is always critical, as well as keeping notes on what works, what doesn't, and why.