to verify the bound of 24 for the purposes of the Gen <F, R,U> God's number, we need to solve all those 25-move <R,U> cases in <F,R,U> in 24 moves or less
what Rokicki did, essentially, is to do them in <F,R,U>, we try to get them down to 24 moves, and if that didn't work, do them in <BR,R,U>...