You can't really cause any damage by un-winding the actuator, but being realistic its near on impossible to drive a RST without even spinning the turbo up!

A standard engine spools up well easy, you can have the turbo boosting even when the throttle isn't open enough to make use of the boost.

Just drive it sensibly, and if you have a boost controller/switch or whatever keep it as low as possible, a little boost won't cause any damage, its also hard not go above 3000rpm, going a little over again won't hurt