This is a follow up question to this one: Exceeded 16 live WebGL contexts for this principal, losing the least recently used one.
In that question, it was found that this error happens when you refresh a webGL tab more than 16 times (or collect 16+ contexts across multiple tabs).
However it is not clear how to dispose a WebGL context so that the browser can free up one of the 16 slots for another WebGL context to be able to go there?