Half-dragon kobolds with dragonwrought fit the dragon magic definition of true dragons yet are explicitly listed as lesser dragons, so just meeting a single definition of true dragons doesn't mean you're done. You should still check for inconsistencies. Meeting a definition of lesser dragon is an inconsistency.
Luckily, I have no inconsistencies. You can't just take one definition and ignore the others. Dragon Magic is one of the definitions (but note that when it was printed there were absolutely no non dragons with 12 age categories), but you can't just ignore Draconomicon like that. You have to put them together.
The Draconomicon definition checks if you are a dragon and get more powerful as you get older. If you do, True Dragon, full stop. If you do not (you are an "other creature"), you check to see if you lack age categories to advance through. If so, you are a Lesser Dragon. If you're True by the first part, you never touch advancing. The Dragon Magic definition is irrelevant to this part, so I'm not sure why you're confusing the two... it's a second qualifier. It's not randomly inserted in.
The Dragon Magic definition just says you have to have 12 age categories, and be a dragon.
Putting these together, if you're a dragon with 12 age categories who gets more powerful as you get older, you're a True Dragon. If not, THEN you check to see if you "advance through age categories." If not, you're a Lesser Dragon. There's nothing defined for what happens if you're not a True Dragon and then fail to meet the Lesser Dragon requirement.
By the way, where does it say Half Dragon Dragonwrought Kobold is
explicitly not a True Dragon? I looked for that but didn't see it.
Closer to implicit, actually. It's still random, so you could roll worse than by rolling 4d6 drop 1. It doesn't explicitly say "higher stats = higher power" and it does not necessarily lead to a so-called "more powerful" character by your own definition, so it's a very flawed.
...it's a stat generation method that gives higher average stats than all other rolling methods. That's the only difference between it and the other methods. And it's called "High Powered Characters." That's pretty straight forward. What other possible meaning for "High Powered" could it be? The only difference is higher average stats!
JaronK