Framer,
If you have had an indication of a cargo fire and carried out the checklist airborne, and after landing neither the Fire Rescue folk or the Cabin Crew can find evidence of smoke or fire, would you taxi the aircraft to the terminal aero bridge or disembark using stairs away from the building?
Hmm. Given that I have no idea how to assess if the cargo fire indication is real or not as I don't know how high temperatures in the either compartment (737) would or could be sensed reliably by the crew or passengers.
We have an added complication in that we have no procedure for a precautionary disembarkation without stairs. Leaving only a full blown evacuation as the injuries that go with it. Any attempt to try and organise an orderly disembarkation with the slides just runs the risk of creating confusion with no clear trigger as to when that should be escalated.
I would not take the aircraft to a jet bridge, a remote stand could be a possibility but then additional coordination, delay and communication issues with regard to placement of stairs is an issue, and without knowing how to quantify the situation how could I find that acceptable?
I'm afraid, I would stop the aircraft. Use standard cabin calls and evacuate. Then face the music and dance.