Anyway, to get back to the question at hand: frenchyge is right, i.e., there is no official upper limit to level 6 (or what Cycle-Smart calls "high"). Rather than get caught up in this, though, it might be easier if you just state your pursuit power as a percentage of your functional threshold power, and we'll go from there. (FWIW, a 3 km pursuit is typically contested at a power that is 125-160% of functional threshold power, with the exact percentage being heavily dependent on your anaerobic capacity.)