Once I got my Mianne lift bridge adjusted, there is no issue with cable slack.  I think your tangle of cable is because you have too much cable on the reel.  When the bridge is down and you're seated, there should only be a couple of turns of cable left.  My cable is never slack at any point in the travel, that was the whole point of the spring loaded switch.

Here's what my cable spool on the winch looks like down and up.

Bridge Down and Seated

Bridge Fully Up