I've been running PVS-14 side by side with thermal since May 2014 ... so 17 months ... mostly by holding the thermal up to the right eye while the pvs-14 is on the helmet over the left eye.
I am right eye dominant.
Based on that experience I now believe:
01 - The dominant eye will dominate. This is true for MKIEB and for dual PVS-14s and for thermal + PVS-14.
02 - The significantly brighter device will dominate.
03 - I can switch back and forth between the devices by sending "signals" to my eyes.
So, it is rare for both eyes to be seeing at the same level at the same time ... whether it be MKIEB, Dual 14s ... or 14 on left eye and thermal on right eye.
With our MKIEB we have two unequal elipse shaped images that our brain sort of merges ... but retains the outer edges of both as well. Close and open each of your eyes individually and compare the individual and merged images. The "merge" of my MKIEB is not perfect. I cannot get even the overlapping portion to align, but that is me. But the dominant eye dominanting means that I don't see double, or even think I do (even though really I do).
With one 14 and one unaided eye ... you get at least some ghosty shadows from the unaided eye ... and I actually think that helps a lot. The 14s in the dual mount do seem to align even better than my MKIEB. The dual bridge cannot colimate the two 14s ... but it is closer than my MKIEB.
With dual 14s we mostly give up our peripheral vision and we are looking through poorly colimated binoculars with greatly reduced FOV but we get twice the amplified light versus one tube ... so we can see better ... and we get depth of field, so we can move with more confidence, hence faster.
With my old Apollo held up to the right eye (as a handheld monocular) and a 14 on left eye ... I could not get the merge to work too well, due to larger bulk of the apollo, but I could switch back and forth at will and that was very interesting.
I did get headaches ... and for a long time I thought it had to do with looking through thermal and 14 at the same time.
But then I got the idea to use the OEN Custom pallet and that was a game changer. With the dramatically reduced brightness difference between the 14 and the thermal ... the headaches disappeared 90% ... splash on my face was much reduced and battery life increased.
In past 1.5 months. with the q-14 held up to right eye with 14 on left eye ... I have been able to get "perfect" merge meaning both eyes are aligned ... a tree in one eye is in exactly the same positsion with the other eye. Of course I am still and holding the q-14 in exactly the right position. Note this is better than I can do with MKIEB, at least in my case.
The right eye dominates and the brighter device dominates, but if I turn on the ir-laser I can see it, with the left eye.
So from where I sit, it can be poor man's fusion ...
But what would make it much more practical is getting the q-14 monunted on the helmet in something close to an optimal position. Doesn't have to be perfect, but 5% near perfect would be the goal.
I belive PAS-29 can do it ... and I believe ATN can do it ... but not sure q-14 or ir-patrol can do it ... and that is too bad ... because q-14 and ir-patrol are certainly the better thermal units. But apparently helmet mounting with a PVS-14 was not part of the design of either unit ... it was for both of the earlier units ... the pas-29 and the ATN but not for either of the later units ... how about that !!