As to toning down the brightness, yes that is an important area!
I've walked around a lot with the Apollo held up to one eye and a pvs-14 on the other and after a 2 hour walk (with thermal held up maybe 80% of the time) I got headaches. Gradually, I learned (by accident?) that switching pallets to "sepia" or "Custom(OEM)" got rid of 95% of the headache. With the apollo on "Custom(OEM)" (what I call "red hot") the white hot was one click away, so if I saw something I needed to checkout, I could switch to white hot easily. Also from white hot, black hot was only 1 more click away. Sometimes best ID results are with white hot and sometimes with black hot, so being able to switch back and forth is good. But either red hot or sepia ("brown hot") works fine for initial detection.
This is also an area where Aaron's new FILTERS should help a lot, if we can get them on the rear ends of our thermals.
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Having the i2 and thermal images side by side (by holding up manually so far) is interesting. It seems "the dominant eye dominates" ... I run a pvs-14 on the left eye, so the thermal, if present is on the right eye. I can either shut one eye to be sure I am seeing through the other or usually I can just "command" the other eye to see and it will. But to see a "poor man's fused image" for me is mainly getting them to line up. Which I can do perfectly with the q-14 and a pvs-14 by holding the q-14 in exactly the right spot at exactly the right angle.
My MKIEB are not perfectly aligned (birth defect) and in fact my dual 14s line up better than my MKIEB, but I usually don't notice the MKIEB miss alignment due to "dominant eye dominates".
But if I get the brightness tuned right (I use sepia on the q-14) and the position right, then I am fused and a tree at 30yds, is in exactly the same spot for both eyes and no headaches. That is the goal, to get a helmet mount that can get at least close to that.
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If you want to approach the goal of not having to check zero of your setup after installing or removing clipon, then precise alignment is part of that, but so it lots and lots of practice, putting it on and taking it off and checking zero each time and taking notes. I take up fore/aft slack by mounting optics as far forward as possible and left/right slack by mounting as far left as possible. I usually see more offset in windage after remounting than I do elevation. But I check zero everytime and note the results and try to get more and more consistent. I don't expect perfection, like the marketing hypes say, I practice towards increasing repeatability instead.
Having a day gun and a night gun is another option and I'm closer to that now than I have been, well several day guns and several night guns. But, I repurpose a lot also, so last months day gun, is this months night gun.
But if you want repeatability, practice needs to be on the path.
