One of my freinds done the comparison. He find HYT 9.1's simulation result is huge different to 9.0's on same pcb. Also He find a very strange symptom. If you set the board's volume fraction of copper to a large value such as 0.89 above, the results of component all reach to 990 Degree or reach to Zero.
I hope anyone having HYT 9.1 copy help us to validate this symptom.