Yesterday was wash day, not because it needed it, but so I could compare and share the fit. I washed it with half a dozen other wool items (none were 100% wool) in our top load, no agitator washer set on cold water hand wash using Woolite, the laid flat (in half) to air dry.
It did size back up a bit, about halfway between day one (fresh out of the package) and day five (sitting & normal activities). I could feel the sleeve cuffs were tighter and I had less extra material around the lower half, but felt less difference in the top half.
I had hoped it would not feel quite as scratchy, but that didn't happen. Good thing I will be wearing with a base layer of at least short sleeves most of the time. It also has a bit of an odor - I'm hoping a couple more washings in a Nikwax Wool solution will help that. Woolite was all I had on hand and I wanted to get the first washing done.