For proof reading long sms messages, I believe it would be better to not have a 'compose window' constricting the new message height. Just alow the previous message to be push up vertically as much as needed just like received and sent messages.

It would make it so much easier for proof reading and help seniors and non tech savvy users. Get rid of the box compose window. It complicats things imho. Even now, I am composing this feedback in a window.