While reading this thread I also looked at the description of the PV adjustment procedure in the tuning section:
If I understand that correctly the PVs are fully opened already at 2500 rpm? Is this true? Does that mean that above 2500 rpm there is no difference in behaviour to an engine that has PVs stuck in the fully open position?

If the PVs only have an effect below 2500 rpm, I wonder why Honda cared to design such a system.

Which part is it that I don't understand?

gepe.