Giving the harpoon some bonus damage based on the force applied to the targeted ship, with a minimum threshold a bit above the pulling force it can produce by itself.
With the changes to its mechanics removing the old turbo ramming assist nature of it I think it could be made to do significant damage and this way avoids turning it into the short range wide arc mercury substitute that a direct damage buff would make it.
I don't think harpoon-chute vent-moonshine-flak squid should be anywhere near the new meta but I think it could be fun to make it possible (just don't let them harpoon you back while you pull that maneuver)