From this question,
setw -g mode-mouse on
allows mouse scroll in tmux. This also causes mouse highlighting by click and drag to be controlled by tmux. Most of the time this behavior is benign and it's sometimes nice to mouse highlighting and keyboard highlighting send yanked text to the same clipboard. The problem I run into is over ssh I now don't have a way of copying text to the system clipboard by highlighting with the mouse.
Is there a way to not have mouse highlighting controlled by tmux or send tmux highlighted text to the system clipboard over ssh?