Congrats on the new smoker! As with any smoker there will be some quirks to work out and the MES is no exception.
1. It's max temp is 275F so if you do chicken it is likely that you will have issues with edible/leather skin. Some report no issue, others do (I had issues).
2. The MES smoker and meat proves are going to be OFF! It is well known issue with MES but you have the TP-20 so you should be good to go. You can use 1 probe as a back up smoker probe to get the temp at rack/meat level and the other probe as a meat probe for IT of your meat.
3. The MES has hot spots and temp swings so you will just need to figure out your smoker behavior. The temp swings seem to be a designed "feature" lol.
4. The A-Maze-N Pellet Smoker tray for generating smoke will likely be your next purchase. It will give you set and forget smoke generation for a max of 9-12 hours if you need. It can also generate double smoke which is awesome to have.
5. If you plan to do smokes at temps of 200F or lower your MES will likely not be able to produce smoke with the on board mechanism (chip loader and heating element). The heating element just doesn't get hot enough long enough to burn up/smoke up your chips. See the previous point about the
AMNPS... it will solve this problem real quick. This way you can do low temp smokes like sausage and bacon, etc. or cold smokes where no heat is applied :)
6. If you must have an extension chord get one that is 10 AWG wiring and try not to no longer than 25ft (though it can handle longer distances). That should be able to supply you enough power so that the unit is not starved by an inferior chord.
7. In the situation where you just can't stand the temp swings or you can't hit your max temp there is a simple rewire option and the use of what is called a PID controller that blows away the MES controller when it comes to holding temp and not fluctuating. I only mention this in the case that your system misbehaves and MES support doesn't provide any help that fixes your issues :)
I think that about covers the major quirks of the MES. Best of luck and enjoy it!