Look, I love Smart as much as the next guy and he does make "winning plays".
But if some team offers him something along the lines of 4/80M+... then I'm not losing any sleep if Ainge decides to let him walk at that price.
I'd hope they keep Smart and keep him around 4/72M at max, but they will also need to pay guys like Brown, Irving, etc. in the future as well to keep them around.
I do think Baynes will be offered the full MLE and I think he'd accept (barring, god forbid, a big injury or something).