The SMS window will scroll down to only show the most recent message once one has been sent or received. This behavior is annoying as it takes most of the conversation off screen. The behavior should be changed to place the most recent message at the bottom, maximizing the number of recent messages that fit on the display. Or, better yet when a new message is received a popup message should appear in the bottom right corner indicating that there is a new message. This mirrors the behavior of other messaging apps, and makes it less disorienting for the user as the window does not just scroll without user input.
This issue is exacerbated by the scrolling problem reported in https://bugs.kde.org/show_bug.cgi?id=508217. The scroll wheel doesn't work properly (on my system) and I don't think there is a key binding to scroll the messages, so the only way to show the latest message is by clicking and dragging the scroll bar. Automatically showing the most recent message at the bottom, like other messaging apps, would be nice.