• 'finish' can be emitted after 'close' if destroy() is called inside a'prefinish' handler.
• 'prefinish' has different timing (sync vs async) depending on whether Writable implements _final which can cause problems such as above to occur or not occur. (stream: simplify Transform stream implementation #32763)

I assume 'prefinish' is mostly used internally so it's probably not a huge issue.