Question:
I am seeking opinions as to what a "typical" (acceptable) ground fault resistance threshold might be with respect to "typical" addressable fire alarm panels.

Are we talking 10K ohm ? 100K ohm ? 1M ohm?

Also, in the event that a "high" (1M ohm) threshold is determined, what types of problems could one expect?

Answer: -My opinion is that if you can measure a ground fault with a 20M ohm meter then you have a problem and you should locate & remove the source of the ground.

-Ground faults no matter what resistance levels should be corrected. The most common ground faults I have ran into on addressable panels involve shielded cable. The sheath tends to cause more ground faults due to the shield and the wire when pinched causes high impedance ground faults. Many times this will cause devices to show up missing due to voltage levels being pulled down