The Vampire pilot talks of a then-secret ability for the Vulcan to immediately generate full power. When I read that I assumed it to be either/and/or the Take Off / Cruise switch and the JPT limiter switches, either of which would help out in times of need but I stand to be corrected. I was not aware of them being secret.
Pages 16/17 and 51 of the link
http://cdn.justflight.com/support/ma...Mk2_manual.pdf