When typing a draft that's a response to an existing conversation, the draft appears at the top of the conversation and refreshes frequently as you type, sometimes jumping to another part of the conversation. If you have the original message positioned in such a way that you are trying to reread and respond to what someone else said earlier, this is extremely distracting. But turning off autodraft saves would disable a useful and important feature.

Since you can see the message you're typing in the edit window, there's really no need to display the draft at the top of the conversation list anyway. Please allow us to hide the currently-open draft from the list until the message has been sent.