PT,
Just going on what I'm current on (777), the NNC doesn't really cover it going out or staying on-once the fire is detected, the NNC should be completed.-As to the extinguishent clearing,quite the opposite. The compartment ventilation is by-passed, and the bottles are sequenced to keep extinguisent in the hold, so it's unlikely the condition would clear even with the fire off.
That being said, the Aeroplane is 330m ETOPS based on the idea it can contain a cargo fire for that long, so, absent any secondary indications of an imminent cabin infiltration by smoke or flames, taking a minute to assess and maybe do a Precautionary Disembarkation would seem sensible.