Been a while since I really read up on all this, so I might be mistaken...

But, I though that if the upper end of the hotend, where its fins are, got too hot, that it would cause the filament to melt a bit in it and start to stick, causing jams.
That is the main reason I have been afraid to go over 190
That is why I went ahead and installed that upgraded cooling system shortly after building it.

The other day was my worst jam ever, after if was printing for about an hour. I left it overnight.
Next morning, I heated up the nozzle, and when I went to pull the filament out, and it snapped off, down in the metal part a bit,
So I had to poke a guitar string up through the bottom to force the filament out.