The gauge adapter seen on first page, will probably not work at all, those white valve adapters are for Halkey Roberts air valve type. For gauge to read well must keep valve pin open.
If having diaphragm air valves need a Zodiac propietary pressure gauge, which has a different middle fitting that pushes diaphragm pin slightly open to read properly. Having pressure relief valves on tubes not an issue which inflating method you employ. If using scuba tanks open air valve slighty while filling, you don't want full 3K psi blowing your tubes as ballons..