Agile Requirements Designer 2.8 was released.
It has new optimization in Path Explorer. You can select new or known optimizer. However, new optimization may decrease coverage .
Agile Requirements Designer 2.8 GA (2.8.000.17)
New optimizer didn't include a part of new feature.
Fixed on new build - 2.8.000.18.
If you want to get it, please open a support case or wait for next release.