Yes, I can tell that you have been putting a lot of work into his proper care. Kudos to you for that! And don't feel bad about the whole 'whisking him away' thing, it happens to all of us. I know it took me years to get the gumption to stand up to a vet... And I learned to do it the hard way when a bird I had rescued was misdiagnosed and the vet kept on telling me he was fine when I kept on bringing him back because I KNEW there was something wrong with him. I finally went to another avian vet [the best one I've ever had and not even board certified!] who did more tests on him and diagnosed him right -but, by then, it was too late and he ended up dying a little after that. We are raised to respect authority and knowledge [at least, the older generations are
] and not to question people who are supposed to know better. But the problem is that avian vets don't really know that very much about birds [because nobody does!], and they are all trained on dogs and cats first and never actually even go to school to become an avian vet so the greatest majority of them treat birds pretty much like feathered mammals. Hence, their proclivity to use Lupron and other medicines that are not really good for birds.
Now, the thing about full spectrum lights [for birds, plants or whatever] is that, as the light industry is completely unregulated, there isn't a standard or even official guidelines as to what constitutes 'full spectrum'. In my research, I have found that one needs to pay attention to the specifications of each light source [something that, unfortunately, is not easily available in some brands]. There are three specifications when it comes to light quality:
1] the CRI [Color Rendering Index] which tells us how faithfully the different colors are seen under that light. The best is 100 so the closer to this figure, the better [I always strive for, at least, something over 93].
2] the Ktemp [Kelvin Temperature] which basically tells you what is the actual 'color' of the light. Lower Ktemps make for a redder light and higher Ktemps make for a bluer light. Birds are more prone to breed under redder light so, although the Ktemp of sunlight at noon is around 5500, when one has a hormonal bird, it's best to expose it to a higher Ktemp so as to make the light bluer [I would say something in the 6,000 - 6,500 range]. As an FYI, red light transverses tissue much better and faster than bluer light so, when we are talking about birds which have photoreceptor cells deep in their brains, the redder light affects them more than the bluer light because it needs to go through the so thin to be actually translucid bones of their cranium and the brain tissue - how cool is that, eh?!
3] the Spectral Distribution which is like a chart of how much of each light [or wavelength] is on that particular light but, unfortunately for us, this information is never accessible to us.
So, check the bulbs you have and see if you can come up with the specs for them and, if they are not what would be best for him, get some other ones that would.
On the light schedule question, the main thing is that they are exposed to twilight for, at least, 1 hour [I do it for 1.5, actually] with no artificial lights whatsoever so they only get this 'different' natural light. You are already doing the 'complete darkness' thing after so that's good.
As to his calming down when he is toweled... I don't know exactly why that is but it might have something to do with the fact that you cannot really touch him much and, as they need touch to produce the 'love hormone', this gives him a sense of wellbeing. Parrots are very reactive to feelings produced by hormones - which is something that people believe is one of the reasons why pluckers pull their feathers - the pain of a feather being pulled by the root makes the body produce endorphins which, in turn, creates a sense of wellbeing [as an interesting FYI, the word 'endorphin' is actually a contraction of 'endogenous morphine' meaning 'morphine' produced by the body] and, in their depression, anxiety, dispair or whatever it is that makes them pluck, they become addicted to it.