That saying applies here for sure ,, I did new brake lines with my portals on a x3 and tried to vac bleed these
I had already known about the AGM and cap setup from the forums ,, well bleeding was going poorly so bought this kit and 3 days later I had it , 30 min later my brakes were all bled ,, flawless and if you buy a 45* 1/4 npt you can use the AGM fitting with a windshield in place