When I read a Word document with this setting enabled the caret lags far behind the reading. For example, I read three pages and tap Control to stop reading. Pressing the read-line hotkey usually reads the entire paragraph that was being spoken, although occasionally it will read only the line. I then arrow right once and read the line again. This puts NVDA back in sync with the actual caret position, which is a page or so back from the reading position.
I tried upping the caret movement timeout to 200 to see if it would help. It didn’t. Then, just out of curiosity, I cut it to 50. When I did that the caret remained on the first line of the document.
I’m using a OneCore voice. This is on my desktop with a quad-core I7 overclocked to 4.5 GHz. With 32 gigs of ram.