Anything which supports multi-line input shouldn't submit on enter it should submit on button press so anyone can use it instantly without learning or remembering anything.
Then make it easier for users to learn that they can enter more quickly with control+enter which you can advertise via tooltip or adjacent text.
Better that 100% find it trivially usable even if only 75% learn they can do it faster
Then make it easier for users to learn that they can enter more quickly with control+enter which you can advertise via tooltip or adjacent text.
Better that 100% find it trivially usable even if only 75% learn they can do it faster