Thanks, the modesetting driver is part of the main Xorg package now.
Without the i915 module installed, unaccelerated Xorg works fine unaccelerated with or without xserver-xorg-video-intel.
I built Wily's release of xserver-xorg-video-intel on dCore-xenial, though that did not make a difference. I see that a new file exists in Xenial and Yakkety - /usr/lib/xorg/Xorg - that needs to be copied as a real file to the filesystem and then made suid root. Or else Xorg will start and the desktop visible but be at a hard freeze unresponsive to keyboard or mouse. I have adjusted the needed startup script for the package xserver-xorg-core and re-importing and SCEs that contain xserver-xorg-core should let intel video work with graphics-4.2.9-tinycore installed as well as xserver-xorg-video-intel. I will be able to test it tonight for myself, but it should just work.