Smart apostrophes work as expected most of the time, but if I have something like She had, and I select the he ha-part and type a single quote, the result is she’d, not the expected she’d you get if you type s+h+e+’+d.
Edit
It happens randomly. I just the exact same thing in another part of my text, and this time I got the expected smart quote.
That said, I’m 100% sure I sometimes get a standard apostrophe.