When I switched from a 053 to the OS 2050 temps dropped 20 degrees and I gained mileage. The mid screw adjustment dropped it down to the 220-240 range on mine depending on weather. This is in the midwest where altitude is not an issue. I can see how that would be a problem, thin air so you have to run lean and thin air to try to cool it off.
I run a Collari B3 (with RB carb, and restrictor) with an O.S. 2050. It makes awesome power except the top is a little flat. I just run 1 tooth up on the bell and its perfect. This combo has awesome low-mid power. And great fuel economy.