I dont have a lagacy VF11 turbo. I have the STOCK VF7...and was running 15 PSI. If you keep boost At or UNDER 11 PSI...you will be fine for infinity. I have run the entire Dragon and Cherohala skyway 100% at 11 PSI. Thats QUITE a beating on the car. the dragon is 11 miles, 318 turns, tight twisty road course style perfection. The Skyway is about...of...25 miles if ultra high speed road course style stuff. pretty much 85% of the Skyway is WOT....where as the Dragon is about 60%. I had no problems keeping up with a stock STi on the Dragon...skyway was...well, more of a problem but he never got more than 1/4 mile out front.
You will be safe with a VF11 at 10 PSI im sure of....especially if you've got a good intercooler setup. With no IC? Dont run more than the stock level...wish is 6.5~8 psi.
We shall test that VF11 safe at 10PSI in less than 4 weeks