Tube should go from where you tapped into the charge side right to your gauge. Little tip put a little bit of cotton from a qtip in the line to avoid gauge rattle from the boost. If it’s a mechanical gauge.
The pic at the top of the thread are vacuum tubes and shouldn’t be used unless you only looking for vacuum. Diesels do not make vacuum naturally which is why they have pumps run by the cam. Most ASV delete kits have a hole tapped for a boost line. Maybe look into one of those unless you don’t want to delete anything.
Ps use a small amount of compressed air to move the gauge not a vac pump.
Can always take it off and tap it yourself easy and will be a better place to put it being aluminum.
Probably sticky veins more than the actuator. They are electronic on brms.
Have you had the oil checked for cam wear?
Oh boy you need to change that ASAP. I’ve done 2 and they aren’t bad.