I tried running my tallas at the 140 setting with a lot of sag to get 120, rides teriable. Braking, cornering, riding seeps all compressed the fork so the bike was super unstable, overly firm is better than overly soft.
What are you not happy with in your current tallas? The foat will have the same spring rates and damper as the float, so I woudn't expect there to be a performance advantage.
You could save youself a ton of money and just send your current fork into PUSH for a rebuild, and custom tune. They may be able to swap our lowers to allow you to run a different axle if that's what you are looking for. They can also replace broken parts if that's the problem. Your fork will perform 2X as good as currenly with their custom tune.
I've got an 09 stumpy.