You have a point there about CBA features.
I didn't realize Dragon armor didn't get healing as a feature though, when gunzosha did.
The healing as a power armor feature is really weird, TBH. Oh, I can see something like it for gunzoshas, but it would be to stop bleeding and prevent disease. We are talking about effectively supermortals here, primarily. Limited wound penalty negation also makes sense. But full up regeneration is unusual, even among the media sources you usually draw on for power armor inspiration. That before you get into balance which is kinda a 'haha NO' thing. Ok, not quite, but armor the regenerates you in combat is probably at least artifact 4 on its own, if not out right Artifact 5. Armor that heals you is really cool, and the sort of thing that feels fairly mythic, like Arthur's sheath. Either way, from balance or themes, its not some thing that should be slapped on as a submodul for power armor.
On the more general FA and maintenance, I imagine it was a mix, at least as far as Solars (and other Exalts) personal gear goes. I can easily see an Exalt being annoyed enough to Ragnarok proof their stuff just so they don't need to fix it ever again. On the other hand, FA!Tony Stark is going to do maintenance on his stuff because he likes to, and so he can figure out what to do better for next time. Also possibly to squeeze more performance out of it. Still others are going to have gear maintained by a buddy/friend/professional, who either don't care to spend the effort/resources to Ragnarok proof, or deliberately don't for various reasons. Mind, this is personal gear, which is to say having roughly as much in common with the run of the mill stuff as an endgame super prototype mecha has with the mook mechs. As you go down the scale to say, gunzosha, you probably see a drop off of Ragnarok proofed/super prototype gear as it needs to be mass produced and useable by mortals. Given those two constraints, you need gear the is fixable by mortals when shit inevitably goes wrong with their gear. There's still probably a range for maintenance, from Russian 'it-will-work-come-hell-or-high-water' to the more American 'here's the manual and a multi-week course, pay attention or it stops working and you die, but its a really nice piece of gear if you take care of it'. And if my exposure to people talking about military gear is any indication, people will argue about which approach is better till the Upsuration decides for them.
Also, on the down tech from FA to Shogunate, I imagine the massive number of explosions from the ongoing DB vs DB conflict did the infrastructure no favors. And that's before you get into what sundering what would have been a Creation wide trade network must have done. Add massively pissed off Lunars for a remarkable case of 'holy shit, we lost the capacity to do what now'. Lack of maintenance probably took a bit to kick in compared to all that.
(Though most of this assumes Art of Permanence is in a less stupid form. Seriously, why is this a costless permanent charm when you made a shiny section of artifacts balance point they need maintenance. Oh, right, because it was these specific charms that let the Solars be the best things ever for Creation's mythic infrastructure, buy them and you to will have that power. Also DotFA laughs at pitiful things like game balance.)