having the fire fighters feeling the cargo door (in lack of thermal equipment)
Yes, I can see that it would probably be prudent to hold on for an exterior inspection. But I would probably prefer not to taxi anywhere, but stop the aircraft, alert the cabin and simply standby to give the best chance of an incident free evac should it then become necessary. But I'm considering a fire would have already caused significant internal damage for anybody to sense anything significantly unusual from the cabin.
However, the only cargo fire warning event we have had involved the crew taxing to a stand and then the fire crew spontaneously opening the cargo door with the pax on board before declaring the all clear! Not suggesting that is in anyway representative, but if there were a fire...