I assume not remembering the personal room has to do with premium sub. If you logged out on a prem only room and the sub ran out, would the game spawn you back in that room when logging again? Perhaps it would be possible to remember it AND make it spawn you into the lobby only when it detects the prem sub is gone. Coding that could be easy or difficult depending on what would need to be done.
As a workaround, I'm logging off at the stairs near the salon. Usually calm place with less rmt spammers. Another thing with Personal room is that it reduces the max camera zoom, even after logging out and in with another character, so I'm now also used to press the + sign on my numpad to get the correct zoom.