Two extra things:
I have a 2018 Marlin resting on a 16K lift. The boat is 12,500 lbs loaded with 350's so the extra safety margin seemed wise to me.
I also have 20 ft bunks. I think the more hull that the bunks come in contact with and support, the better.
My lift is perfect for the Marlin. I assume, (dangerous word) that an '06 Marlin is the same hull.