In the 1-1.30'o'clock position, you retain your cheek weld and just rotate the gun slightly until the dot comes into view.
This type of sighting does not work well when grasping the VFG. Since you are spending more time transitioning than shooting, it is faster to grasp the forward end of the float tube to kinesthetically point the gun as part of obtaining the dot sight picture.
Mounting the sight further rearward seems to increase the side/side/up/down flexibility of eye placement to still retain view of the dot.
A general note on BUIS and multiple return-to-zero optics. If you have either your BUIS zeroed or one 1x RTZ optic (ie, an EOThing or Aimpoint) zeroed , you can zero the other without firing a shot, in your living room, by obtaining a sight picture through both the BUIS and the dot optic, and then moving the other to coincide with the sighted-in sight.
In this case, I put the XM193-zeroed EOTech (on LT mount) on, then made the Dr's dot coincide with the EOT's dot, then dropped it approx 2" @ 10 yards for a rough zero.
The YHM spacer is a POS. It has to be slid over one end of the rail on which it's mounted, which makes it pretty much useless. I believe the GG&G one might work better. Wish LaRue made one.
[ link to LARGER image ]