Thanks a great website/resource. I know the nema 14-50 was done with a new 50 amp breaker and 8 gauge copper wire and the run is only 12 inches off my breaker box. Either way getting a new charger (grizzl-e) in a couple days and I'll see how the plug/cord heats up under similar load/ambient conditions.You'd have to test current and voltage also. Low voltage on outlet is bad. Out of spec current is bad. Look at line length also. The cable insulation is rated quite high but 170F seems of concern.
nema 14-50 normally means you have a 50 amp circuit so you'd need to look at the type of cable and how much it fills conduit or other issues. Examples of various types.
Your local code can't be less than NEC but can be more. https://www.camperrules.com/what-size-wire-for-50-amps#axzz761VW8UPY