@scott Yeah, it apparently ends up frying the magnetron.
Also apparently why microwaving plates is not a good idea to warm them. Saw a suggestion. That you can if you add a cup of water on top. Have to try that. (Apparently also a good trick when microwaving pizza to stop the crust from drying out. Also untested as of yet.) :)
https://products.geappliances.com/appliance/gea-support-search-content?contentId=17934