More info I got from Forge:
"The correct replacement actuator for the 1.8T 225BHP Leon Cupra R KO4 turbo actuator is our part number FMACVAG01. We cannot recommend from a stage 2 reference what you may need and it may be better to ask this question of the tuner who mapped the engine (or the tuner is going to). You do not have to run an actuator in but mapping may be required ensuring the ECU recognised spool up matches the fitted spring – I have included the spring selection
guide below showing the relevant springs and their spool up/running pressures.
http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=&product=FMACVAG01
VAG K04 Transverse 1.8T Adjustable Actuator
T2 actuator spring selection
guide
The following is general information regarding Forge actuator spring tensions and are important considerations when making a decision on which spring you install, especially if you are running a boost controller or have an ECU upgrade.
The 4 springs we offer are listed below under their relevant colour codes and related pressure ratings. Running pressure is the lowest or minimum pressure the spring will operate at, which is important when considering which spring you choose. The spool up pressure is the vacuum pressure required start the spring moving, at which point the turbo waste-gate will start to open (spool up).
The actual rating for these springs is as follows, the lower pressure being the spool up pressure and the higher pressure being the running pressure:
RED 17 psi (spool up) - 20 psi (running pressure) our product code FMAS049R.
BLUE 14 psi (spool up) - 18 psi (running pressure) our product code FMAS049B.
YELLOW 9 psi (spool up) - 15 psi (running pressure) our product code FMAS049Y.
GREEN 5 psi (spool up) - 10 psi (running pressure) our product code FMAS049G – fitted as standard replacement.
The spool up can be altered to a higher pressure by adding more tension to the spring. Be careful not to add too much tension to the spring as it will become coil bound, affecting the rod travel and thus affect the waste-gates ability to open effectively. There is a common misconception that the operating pressure of the spring can be increased by mounting the actuator rod to the waste-gate arm in such a way that the spring is under more load than the recommended above. "