Dungeons are full of exploits/bugs everyone who runs some of them knows that… Just look at how many exist in Fractals for example.
How about allowing access to the dungeons prior to them going live? No loot drops, no damaged equipment, nothing, just allow people to run dungeons for a while without benefits/drawbacks just to find these issues, essentially some way to beta test them.
A QA team can never surpass a few thousand players, that’s the reason we have beta tests. Allowing players to test any dungeon changes and any new dungeons before they go live would allow the dev team to fix even more bugs than any QA team can find.