These instructions to install the Harken one say to wrap the shroud in electrical tape:
http://www.harken.com/pdf/4438.pdf
They might as well say, cut the wire here... Wire wrapped in electrical tape sounds like a recipe for corrosion to me.
I'm assuming I could have the roller on top of the spreader and put some UHMW tape on the upper surface of my spreader (which is painted with alexseal) to prevent it rubbing the spreader. Wonder if that would work out well.