Is it ok to let something hang from its plug in a receptacle? (electric car charger)
Generally,&nbsp;cables carrying high current for long periods are expected to be fully unwound from any coiled storage arrangement. This is certainly true of ordinary extension cables.

It is generally not OK to hang heavy loads from power outlet sockets. Regardless of the design of a cable and its storage accessories, the sockets are likely to be designed to carry the weight of the plug and sufficient cable to reach the ground. I'd expect the designers to make provision for people tripping over the cables, pulling on them and driving off without detaching them. However it is likely that the intent is to reduce the likelihood that any consequential mechanical damage to the socket subsequently exposes people to an electrical hazard.

For $72 you can obtain the J1772 standard and find out if it specifies the mechanical strain that the socket should be designed to withstand. In the EU you'd check standard IEC 62196‑2.