It is going to come down to what is acceptable to you and what risk management options you have available. Has a recent hobbyist who purchased 25 lbs of KP Aquatic live rock I just put it in my display of 4 years old. My process was pretty simple:
Open box
Smell fresh ocean and dream a bit
Glove up (thick rubber gloves I use when working in my display, shoulder length)
Cough (I'm teasing!) - I mean grab my diving light
Take 1 rock out of box / bag of water and examine over bucket
Place in 2nd bucket
Repeat until box/bag is empty
Examine bag/wager, slowly drain
1 decorate crab (refugium)
2 gorilla crabs (overflow box - I have a lot of rubble in there for pods)
4 red mitrax crabs (just like emeralds but red/pink) - display
In my case there was only one crab that I missed and I'm not sure what type it is or was. Looked like a decorator but maybe a smaller gorilla. I caught it a few days later using a small tupperware container with a piece of shimp in it. That lad ended up in the fuge and is doing ok.
First thing for me to clear up. I wanted my rock in the display as soon as possible because I paid for live rock. I knew stuff may get by me and I also knew the risks. To me why pay a premium if all I'm going to do is kill off the diversity by QT or some other process.
TL;DR - what is your acceptable risk level. Are you comfortable spending a few days setting up traps. If so then in the display it goes. If not, you have some unknowns, or concerns, or not able to, isolate to the best of your ability with quality water and treat it like a display. Then set up traps to capture and move as you deep it safe.
