Does anyone here have enough experience with these to say whether the 4% or so of synthetics in the Don't-Sweat-It polos from Banana Republic reduces shrinkage in any meaningful way?

I just bought one in medium-tall. The fit is great through the body, but it's almost comically long on my 6'5" (but relatively short-torsoed) self. I've had a few Banana republic polos in the past that I really liked, but over time they shrunk up so far that the tall sizes barely reached my belt. That might actually work to my favor here.