-

.

A linear regulator will throw the same heat.

6V bulb on 5V power will live about 7 times longer. This is a VERY common working condition. My ex school specified 130V lamps for 117V power to reduce re-lamping costs.

The flip side is that it is dim and inefficient. However that's moot for small meter lights.

If you have two lamps, put them in series. Same/less heat in the resistor. Drawback is that when one fails, both go out.

+1 to series connection, will save power and reduce heat, while heat in a meter bridge is not a huge problem.

JR