^^^ rick:Hi - interesting observation!
I guess that anything is possible - but it's mighty difficult to comprehend how the addition of a dongle into the OBD port would cause an electrical problem of concern of the ilk in your question. I also guess that there might be a difference in our respective definition of the term "electrical crackling" - to me, it connotes something sinister and foreboding; an electrical fault simmering away in the background waiting for it's time to avalanche into a serious incident. Again, difficult to join the dots by simply plugging-in a dongle and interrogating CAN modules.
That said, I've found that it's not unusual when powering up a cable to hear a "sparkle" sound from the car's speakers as the device interrogates the module @ address hex5F. I've never thought to understand why this happens and I've certainly never been concerned at its occurrence - quite the opposite in fact; I would tend to worry if it didn't happen because it would indicate that the normal hex5F challenge/response dynamic has not been successful.
So, is my "sparkle" noise = to your "electrical crackle"?
Don