Diverter Valve Shimming
Another one of Steve Shwings mods which are now optional extras from Forge as a shimming kit consisting of springs and washers.
Essentially you are tuning the reaction characteristics of the DV by changing the given pressure that allows the DV to close or open.
All you need are 2-3 35mm washers of no more than 5mm combined thickness.
Insert them into the piston to reduce the spring travel and therefore change the opening and closing pressure.
Try 3mm worth before trying 5mm to see what you prefer.
The effect it has is it will close the DV sooner and bring the car on boost sooner.
I will also make gear changes smoother in the way it reacts.