At what pressure does overboost and limp mode occur (vRS)?

Is there a value above the specified boost which causes limp mode to rear its head? I've fitted a BBT actuator this weekend (as well as an SFS oversize TIP, ported manifold and 3" decat) and now too scared to give the throttle too much beef in case I get overboost and limp mode! Or worse.

The actuator was brand new and I was under the impression it was a 10psi one. However, looking at the logs, it is already making about 0.9/13psi without using full throttle and at only 3000rpm. The N75 is also disconnected, so actuator pressure only. I'm using a standard Leon Cupra map, which requests a steady 0.6 bar; this is exactly what was produced with the standard wastegate and N75, so there were no problems there.

I guess I need to take a steady drive to Hinckley?