I was cooking some food when I noticed a burning plastic smell and some smoke coming out of the knob, I let it cool down, and when I turned it back on, there wasn't any smoke but the burning smell returned, is the plate damaged, or is it some stuck food being burned?
The burning plastic smell seems to be coming from the plate, even when it is dissassembled like this, i can smell it from the centre.
That just looks like discoloration that sheet metal gets with repeated heating. I would investigate the controls, there are contacts that open/close as a bimetallic strip heats up and cools off (basic thermostat). if the contact are arcing or stuck it could over heat, also since you said smoke was coming from the knob. . .