The Jr is a time bomb regardless, plus it might have paraphernalia inside it.
Get a bosch 17° or an adrenaline. It's not that the Jr is putting out more then stock pressure, it's the gen3 is so beast mode. In tuning mine I know exactly what a tune calls for, but I'll regularly see 300-500 more psi then desired. Call Matt and ask what the tunes are calling for, he might need to pull it back some. You should also figure out what model halidex pump you put on there. When I bought mine used, I sent it to swamps for a check up and they said mine was 1 of about 5 they built that had a pump "too large" on it. Too much pressure and it caused issues with ipr and wasn't recommend except maybe for sled pulling with huge injectors.