I've just replaced a late 80s stage 2 Turbo Technics turbo with a -31 actuator for a modern stage 3 TT turbo with a -34 actuator. The old turbo was set up for 24psi peak pressure and I have set that on the replacement turbo by reducing the Amal valve's R port (bleed) from 3mm to 2mm dia as it was overboosting straight out of the box. That done, I knew this turbo would be a little more 'laggy', which it is, but I expected a harder hit as boost builds up. If I decrease the diameter of the jet in the C port (compressor), then readjust the R port jet, will that allow the boost to build quicker?

 

this is a guide i once received - and it confirms what you're saying

To increase both the peak and held boost pressure figure, increase the bleed size of the amal valve port labeled “R". (Viewing from the top it’s the right hand one)

To increase only the peak boost pressure figure, decrease the bleed size of the amal valve port labeled "C".(Viewing from the top it’s the middle one)

As a last resort only:
To Increase both boost pressure figures, decrease the size of the amal valve port labeled "W" (Viewing from the top it’s the left hand one) decrease the bleed size of the amal valve port labeled "C".(Viewing from the top it’s the middle one)