Running a flexible drive shaft with reverse thrust?

[HobbeeSwe]

Hi. I am building a 7-foot replica of a WW2 battleship with three 60 mm (2 1/3") propellers. I will run the props using both a fixed 16" propeller shaft (rear part), connected to a flexible drive shaft inside the hull to optimize placement of motors. However, I just relaised that regardless if I use a "left" or "right" propeller/shaft rotation, what happens when I apply reverse thrust (stop/reverse the boat)? Will this damage the flexible drive shaft and is there a way to minimize the risk of damages? Thanks in advance (Henrik, Sweden).