Maybe it might help if I were to explain why I believe there is a vacuum leak.

Based in certain inputs to the vehicle computer , the amount of fuel injected is determined. One of those inputs is the amount of air coming into the intake which is normally measured. When addl air gets into the intake via a vacuum leak, that air does not get measured and the computer cannot always compensate for that.

A quick way to verify that condition is to open the throttle and allow some more measured air to enter and now the addl fuel is added and the problem goes away until the throttle is closed again.and idle quality reflects that.
Try it and see, OK ? If that doesn't help, then we need to do some addl testing.