I did some tests here as well and while I seem to have gotten tear free working, the results are a bit puzzling.
First, I verified that the modesetting driver is active and that I'm using dri3 - still getting tearing and marco complains about xpresent support.
then, I created a 20-intel.conf file in xorg.conf.d explicitly setting the modesetting driver and dri3 for good measure and rebooted, no change.
I also tried uninstalling the intel ddx driver and rebooting, no change.
Then, I re-installed the intel ddx driver and adjusted my 20-intel.conf file to enable the intel driver instead of modesetting and rebooted again.
Now, I seem to be getting tear free rendering (tested dragging windows around and scrolling in firefox, I'm not observing any tears), however if I do marco --replace in the terminal it still complains about xpresent support...
Note: I did NOT enable the tearfree option in my 20-intel.conf file