I've heard they are looking into touch switches and things like that now. I don't think the way the faceplate on shotgun is done would work with a base. You would loose a huge amount of flexibility with the figure and it might as well be power pose or a statue at that point. But if they develop something like near field type tech or wireless power..then that may work.
I think if they had touch switches (if you don't know that's like those lamps that you touch the rim and that acts as a switch..things like that) anyway...if they used that I think most people (never gonna please everyone) would be happy. You wouldn't need to pull pieces off to turn it on and off. Still have the modular design and battery's.
that sounds like a good start. sort of like baby steps. i think i'll be happy just as long as they continue innovating. we've come a long way in just a few years.. from the standard iron man lights, to shotgun's facemask, and now the 46 is chock full of light points. hell.. i honestly didn't think the MMS 46 was actually going to have all of his lights.
the technology for something like a wireless phone charger exists i assume the same principle could apply here. none of this is really all that practical right now. but i think in 5-10 years, maybe they won't have found a solution, but i think we'll see some sort of advancement.. whether it's the touch switches like you said, or something else. also.. since the legs generally aren't lit, it might be possible to house the batteries for the figure in the base, and have the figure connect to the stand clip in such a way that it powers the figure.
you know, maybe a solution for ultron could've been.. as well as the LED's for his eyes, they could've painted them so that they're still red when the lights are off. and perhaps with the stand, they could've added a light feature to the clip or something so that it would light red through his torso and make it appear the way it's supposed to be with the actual torso lights on.
anyways, all that being said, i think these figures still look beautiful without their lights on. from what you've shown of the 45, it looks like his eyes are still going to be white when the lights aren't on.
so, even if the lighting doesn't see a massive innovation, i think they could figure out some solutions to some of these problems.
... but then again, who knows if they'll ever need to use these techniques again lol.