Welcome to you both! Most of us Don't Spray, Baste, Mop or even open the smoker except in the last hour of a cook to check for tenderness.
Pros...You get to put a little extra flavor on the meat.
Cons...1)Every time you open the smoker you add 15-30 minutes, depending on smoker, to your cook time. Temp has to recover to proceed.
2)On top of opening the door adding time, Spraying or Mopping adds MORE time to the cook! All that liquid is going to evaporate and as it does, Evaporative Cooling, what you feel when you are sweaty on a hot day and you sit in front of a Fan to cool off, sucks heat out of the meat. Cool the meat and it takes more time to get cooked.
3)Most here are Bark Sharks! That dark brown crust on the meat is the best part. Spraying inhibits a nice crusty Bark forming.
4)Spraying, etc, does nothing to keep the meat moist. It evaporates before it soaks in. Injection or Brining for Poultry is the only way to add liquid and moisture
5) Basting only makes a difference in a High Heat cook of large hunks of meat. Basting a Whole Pig or Lamb on a spit over a 400°F Fire. Lets the interior cook without burning the Skin.
Spraying, Mopping, etc in low and slow smoking is pretty much a technique that has been passed on from the days, generations ago, of Open Pit or Open Fire cooking and smoking over high heat. Totally unnecessary but that's what boys watched Dad do for a hundred generations so it continues. Nothing wrong with experimenting for yourself, but when an all night 16 hour Pork Butt Cook turns into 20+ hours tending a fire...Remember this post...JJ