Having personally flown for several civil jet transport operators, I find that they can be divided into two basic types, where engine fires are concerned.
1. This operator mentions that engine fires are definately not good for ones health, and action to shut down the offending engine, and extinguish the fire at the earliest opportunity, should be taken.
Sometimes as low as 400agl.
2. This operator mentions that engine fires, altho potentially serious concerns, nevertheless should take the back seat to using the burning engine, (if indeed it is still producing useable thrust, which is many times the case) until a reasonably safe height is achieved which, in the FAA's thinking in years past, was at 1500agl.
In both cases, we are talking about pod mounted jet engines, not buried in the wing, Comet style.
MY personal preference is for number 2, as in my opinion, this is the most reasonable.
Individual circumstances clearly could dictate, however, shuting down the offending engine earlier...severe vibration, explosion, etc.