Fact or misinformation?

"i always have a fire extinguisher on hand when i listen to mono lp using my art9"

 jss49- yes, the mono LP's I play on my ART9 sound amazing. IMO, best "value"

cart that gives you an idea what the hyper carts do.

Dave is entirely correct. There is one instance that might damage a stereo cartridge and that is trying to play 78s with it. The groove size is much larger and a modern cartridge will bottom out in the groove encountering more friction than usual as the point digs into the shellac. 

I do not bother with mono cartridges. A stereo cartridge will play mono records just fine. Imaging is not important as there is no image. Mono records actually sound best off axis.

How can it possibly make any difference whatsoever if both sides of the groove are identical (mono) or different (stereo)?

Obviously a salesperson with zero in-depth knowledge making ill-informed guesses.

Thanks for the laugh!

NO! 

@intactaudio +1