At the risk of engendering a debate that I really don't want to enter into, I would make a couple of points.

Firstly the respiratory exchange ratio is closer to 0.8. If you don't believe me have a look at the mitochondrial reactions in a biochemisry book.

Secondly I seem to recall (and this is really pushing my memory as the exam I learned this for was nearly 15 years ago) "sorb" contains other agents, particularly KOH, which act to promote the interaction of Ca(OH)2 with CO2. Essentially the KOH is much more active, reacts with CO2 to form intermediate compounds which them react with the Ca(OH)2. This both promotes the reactivity of Ca(OH)2 and also reforms the KOH which them goes through the process again. So I'm not entirely sure that the equilibrium constant you're quoting is the only thing that is affecting the wider outcome.

If you can make a more efficient CO2 absorber, the world, and lots and lots of money, will beat a path to your door. Good luck with it.