The OP was asking about “Making Dark Candi Sugar" and inverted caramelized sugar is definitely not the same. Sure its good enough as an adjunct but not as a substitute.
Very Cool MCWILCR, you are a lot further along than I am. I read a blog somewhere of a guy who actually grew his own Sugar Beets and tried to make refined sugar. His experiment failed to make refined sugar, but I noticed that the syrup that he boiled down turned a rich dark brown/black color and looked exactly like Dark Candi Syrup. I will try to make a friendly call to a commercial sugar beet refiner to see if I can get some of their syrup before they refine it.
Diammonium phosphate (DAP) is not a derivative of amino acids. It is a salt. It is produced by reacting ammonia with phosphoric acid.
I doubt it's worth the cost to make my own, I just enjoy trying to solve a mystery and the challenge to reproduce it.