What is the purpose of the vent on a Maxitrol gas regulator?

Should I detect a strong continuous leak at the vent???

The vent allows the back side of the diaphragm to move freely.

Unless thee is a leak nearby or the diaphragm in the regulator is bad you should not smell anything on a persistent basis.

The odor agent is mercaptan and it takes very little to be noticed.

Thanks.