It's up to 46 fully formed floors out of 56. I estimate it to be 560'+. It's now 8th in the city and Boston's tallest building since the 80's!
There is a mechanical grate across the glass on the 27th floor (helps when counting), and then the floor plans change. This is delineated by a different spandrel-to-window layout on the 4 floors of cladding that are installed above the grate. (no pics sorry) There are 15 more floors above the glass. Just 10 to go! So close!
Just passed Boston's crowns. The 5 buildings clustered at the top of the plateau are next.