While I agree that those leviton recepts are likely made too cheap, I conjecture that a large percentage of devices and electrical equipment would not hold up to 80% loading for very long in the real world.
Residential applications ( lighting, power, etc) are pretty forgiving. For the most part EV charging is about the only “demanding” load that there could be.
No copyrights on "useful articles" like electrical receptacles.
Note that a 14-50 is a 4 wire wiring device.
Yes, code compliant at the time. I have worked on a number of houses of this & previous time period. Even worked on re-wiring one older house on peer & beams that used the old ribbon type TV wire. While crawling under it, there was a piece of ribbon TV wire that I started to cut, but decided to wait, cause it might help me pull in a new TV wire. When I took one base receptacle out, the TV ribbon wire was attached to it!!
Would you please expand on "a level 2 charger" ? Does it have 2 different charging rates or what ?
Can I nominate the idea that a NEMA 14-50 receptacle can be protected by, oh, whatever the heck breaker size you want. Because well, stoves only need a 40A breaker?
Level 2 simply indicates 240VAC. They can range anywhere from 16 to 80 amps. Many can be adjusted. Those that operate at 40A or less can be cord connected and plugged into a 14-50 receptacle. If your customer is asking for a 14-50, his charger is a level 2. The post you quoted is confusing the issue.