To me it seems clear the number of failures is too high. Masterbuilt needs to redesign this smoker.
I for one have filed a complaint with the Consumer Product Safety Commission. If Masterbuilt were going to change on its own it would have done so by now.
If you have had a similar failure consider filing a complaint.
Not everyone has GFCI outlet that will detect bring this problem to your attention. It is only a matter of time before a MES a failed is operated without a GFCI and no ground and somebody get hurt.
If the heating element in your smoker has failed it will need to be replaced. Installing a PID controller will not change the fact the element is bad.
If you wish to wire the new heating element to work with your PID. Connect the white wire from your new cord to one of the elements terminals. Connect the black wire from the new AC cord to one of the terminals of the safety thermostat. Install a wire from the other terminal of the heater to the empty terminal of the safety thermostat. Please be sure to connect the green wire from the AC cord to the steel case of the smoker.
If you value the life of anyone that may get close enough touch any MES smoker be certain that smoker is only operated from an outlet protected by a GFIC Ground Fault Interrupter Circuit that you have tested.