this mod requires the "lucky repair" skill to be activated, since it exploits that to allow infinite repairs. it works with the most recent version (as of 11.9.2019) as i just created this.
usually when doing a grapple, you only have the option to throw a zombie to the left, the right, or behind you. with this, it allows you to also push them forward, which is great when dealing with hordes where leaving your back exposed would be a death wish.