You can tell you are a bird person, just by listening to you.( well by what you write) I too began with a budgie, which developed into a great love of birds..........only not as great as the macaw.
I have had lots and lots of Finches, not only the ordinary Zebra which flies around up north wild, but the fancy ones, and have had great success in selective breeding. A personal problem ( not health ) saw me giving them all away to other breeders who I knew. I have missed them, and am going to begin again soon with the African Fires. I still have some Bengalese in one of the aviaries, with my small parrots. A few Cordons in another aviary, as well with some small parrots. I always followed the rules in giving grit in "D" cups, but found they did not eat it, but loved the baked egg shell, which is always there. Never lost a bird.
I too have hand raised many birds, including the Indian Ringnecks.
These are magic to hand raise. The tiels, they are cute and have hand raised many as pets, and given to my family's children.
I used to mix my own seed I bought in bulk, and they all had a variety of many fresh and dried food. You are right in saying not one bird person will feed the same thing to their birds, and in many good books the Author will say exactly what you said. It is nice to meet you.