Another question highlighted this Space X commentary for the GRACE-FO launch:
Now in order to fly an efficient trajectory for both of the payloads, we’re actually now running the second stage engine at lower power. That means the burn will be longer. For folks who used to seeing us shut down the upper stage engine nine to nine and a half minutes in to flight, today we’ll actually be shutting down the engine just past T+10 minutes into flight. As planned for today, the longer burn at lower power obviously takes more time, but gives us a more efficient trajectory.
The GRACE-FO orbit is comparatively low and circular. Entering it in the usual way, with a boost followed by a wait then a second circularization burn, would have put those two burns about 2 minutes apart. Instead, Space X used a longer single burn.
It could be that Space X wanted to avoid a "hot" restart of the engine. They routinely restart after the engine has had 20+ minutes to return to lower temperature. Has any mission had a restart after a shorter interval?