Correct plug wire gauge to use at a 20A receptacle

[kwired]

... does it matter where in a circuit the overloads are placed? it has been common to find the overloads in a motor control circuit placed in the common or X2 side of a control circuit...

Hurk, I'm sure you are well aware of this but want to clarify a little more.

What you described here is just a contact in a control circuit and not the actual overload sensing device.

An overload protection device itself does not have to directly open conductors of circuit it protects, it can mechanically operate a device that is part of a controlling circuit as is common with magnetic starter applications.

The actual sensing of the possible overload can be anywhere in the circuit. Although uncustomary, it really could even be ahead of branch circuit device as long as the load being protected is all that it is monitoring.