Paste button iPhone as in the iPad. I think there is room
Please vote for this if you’d be interested in it on iPhone. If we did it, it would not be optional, but maybe phone model / orientation dependent. On iPhone 5 and 6 form factors (includes X, XS) there is not a lot of room in portrait mode, particularly now with emoji completions.
McDowell James commented
But please make it optional because I might change my mind