Since the intake before the turbo will be open to the atmosphere then there will already be an open PCV connection from where anything that leaks from the turbo into the crankcase can vent.
Opening the cap will make 0 difference, but you can do it if it makes you feel better lol. Never done it once though.
I know you said "Do not disconnect or block the manifold or do anything else", but I see that in some videos, but maybe they're exceeding 1 bar?
No, they don't know what the fuck they are doing, that's all.
The manifold sees all the pressure from the turbo, why the hell would you disconnect it and not test all the little things connected to the manifold?
Hint: that's where the leak is in at least half the cases.
The only reason to keep it at around 0.5 bar is because you're pressurizing the turbo inlet. If you want to go higher just remove the turbo outlet hose and pressurize from there instead.
But for that you might have to get the car on a lift and remove the bottom engine cover , it might not be accessible easily from up top. I see no point unless you just built a stage3+ project car with full intake and want to do the initial high pressure test before running it, testing it to a higher pressure than it will be running.
Consider the fact that there is over a decade of experience behind these words doing it professionally.
Something random guys doing videos on internet don't have
