I get what you mean. That is why I like to do the test at a higher pressure then the system will ever see. No its not the same exact thing as a boost spike but its better then nothing.Yep I’ve done the same things as you. I had a spare 2.5”-3” silicon coupler and combined that with a piece of PVC end cap and a couple T clamps. Drilled a hole in the PVC end cap where I attach my compressor supply. Allows me to roughly verify my boost gauge is working too. I know I have a small leak out of a corner of my stock intercooler but I haven’t found any other leaks. What I meant when I said I was surprised I haven’t popped a clamp is because the turbo spools so fast it builds pressure way faster than my little 3 gallon air compressor can. That boost spike could be enough force to pop a hose off. Steadily filling from a compressor isn’t a real life scenario.