Just got myself a set of 2012 seats for my 2011 model and thought I'd throw this out there to take some of the guess work out before I cut it down, so could anyone with a 2012-2014 tell me the post height in mm please.
I took mine out and used a shorter st.steel bush with a flat pan head bolt. Did same as you are thinking of doing to my 2011 but with later seat unit. Easy enough to do.