From I have seen some runs clearly reaches 9.9 but AFTER clearing final round (boss round). What I suggest is starting final round with said intensity. But if that category provides said inconsistencies, then it would be the best to discard the idea.

Basically same as other categories such as Classic 5.0 and Classic 9.9, but after finishing Round 6 the intensity should increase to 9.9 and clear Final Round with said intensity.