You haven't loaded it hard enough for it to matter in that case, or have well over needed capacity. It's a fact you loose pulling power every wrap. How much has many different factors. None of our winches here at work have more then one wrap for this very reason. Same reason why full wrap winch draws the most amperage. You just gears it up like crazy with that full spool.
The black bars are for the load leveling hitch, and thats a big not gonna work with how the lines are drawn. I mocked up a few different versions of bars going front, o settled on a single center bar as the best compromise without having to cut the jack apart. Well see this weekend how it works.
10-15% per layer is lost. More depending on the type of winch.
https://www.warn.com/warn-winch-performance-specifications-pulling-capacity-by-layer