This is a conundrum.
If you are concealed, sure, for the most part nobody will know.
Until that is, you need to defend yourself when some very loud noises will probably give it away.
If you think that you won't need to defend yourself, why carry the gun in the first place? Realizing that there is a risk is part of why we carry - not because we expect trouble, but we cannot be sure there won't be any.
The answer might be that you're willing to take the risk of being prosecuted if it saves your life. You're likely to face some kind of legal consequences after a DGU in NJ, whether it is criminal or civil regardless of what the county prosecutor says. It will help your case if you start from a position of legally carrying rather than not.
Another answer might be to just not go there in the first place.
Everybody has to make that risk assessment for themselves.