All this shows is that JC doesn't understand the consequences of 'instantaneous' either!
Since you started this most recent run with the following i think it helps to repeat it...
"One thing about how players seem to think 5e works just astonishes me, and I believe stems from 5e's lack of wording; something that players of 3e would not do... ...and that is: not realising the consequences of the 'instantaneous' duration!"
You then went on to make a lot of claims about what a duration of instantaneous means even in terms of in-game choices - and not one rule cite from 5e to support them?
Is it possible you are dragging 3e rules definitions into this - is that because thats something 3e players would do or how it worked in 3e?
As for your retort about JEC and whether he knows what instantaneous means... this is from the notion of 5e rules, 5e terms and what that means and he answered that clearly in the Sage Compendium. That was already quoted.
But what was not quoted as recently was this...
"Official rulings on how to interpret rules are made here in the Sage Advice Compendium by the game’s lead rules designer, Jeremy Crawford (@JeremyECrawford on Twitter). The public statements of the D&D team, or anyone else at Wizards of the Coast, are not official rulings; they are advice. Jeremy Crawford’s tweets are often a preview of rulings that will appear here."
So, the publishers establish an official source for 5e rulings.
So, that source provides a clear example and answer that directly contradicts your long run on about "how players seem to think 5e works" and then go about trying to show how it really works.
Maybe, just maybe, those 3e players should read what 5e rules and official rulings sources have to say about what instantaneous duration means before trying to tell those players what they know?
Maybe?
But maybe, just maybe, before going off on how many 5e players don't know this or