Scheduling for the Android display pipeline

VSYNC "occurs at the refresh rate of the display, and is thus periodic: a display with a 60Hz refresh rate generates a VSYNC every 16.6667ms." With the newish G-Sync/FreeSync HW introduced by Nvidia and AMD respectively, VSYNC is now effectively an IRQ rather than a clock. Do any mobile devices yet make use of such a dynamic scan-out mechanism? Might being able to slightly adjust the scan-out time help?