Unfortunately I am. I have a 400mm post now that's sitting 10mm past the limit line. This Thomson post is 410mm...so an 1/8 of an inch may make a difference to me...hence this question.

I actually found a BBB post called the Longscraper that's 450mm. I've ordered one from my LBS. That should be plenty. It's not a setback, but at 6'5" with an exceptionally long inseam I don't think I can afford to be choosy - my knees are killing me!

Thanks for your replies everyone.