Created attachment 8191 Xorg.log Screen tearing is present in the upper part of the screen with --vblank=present, but it appears fixed by --vblank=glx . This means that screen tearing is present by default on Fedora 29 on my hardware (which admittedly is old). Since xfce should eventually switch to Wayland, I suppose that the glx may actually be a better default. xfwm4 version 4.13.1 (revision 942156e4) for Xfce 4.12
We're not going to do a per hardware table to see which method works best. But I'm somehow surprised that Present doesn't work with intel. BTW, as an aside, your comment seems quite confused, Wayland is completely irrelevant here, xfce is not going to switch to Wayland. Wayland is a completely different architecture which implements its own display server within the compositor and window manager, completely out of the scope of a small project such as xfce. Oh, and glx is completely irrelevant for Wayland as well.
fine. My comment on wayland was more along the line of Xorg is eventually going to be replaced and so xpresent is going to vanish.