No emotions, just logic. IO and RC are among the longest standing and most widely used salts. It's a fact that you can grow and maintain a spectacular with with them. How urchin embryos react it it doesn't change that fact.
No emotions? I mentioned 'American salts', you only mentioned IO and RC. Only a small amount of associative logic in that comparison... It's geared by emotion/opinion.
Further you quoted the AA article and wrote off ANY possibility of negatives with any other organisms. That again is emotion, not logic.
With the other data available, given AA is only a single source, the possibilities go up that lithium interferes with other biological development in negative ways. We are growing coral, breeding fish, raising planktons, life goes on, and to better understand it only furthers our success. Pretending it doesn't matter is the most illogical attempt for a point of argument, thus it's geared by emotions. Perhaps you need to learn a bit more about yourself and why you bring up the points you do, because it surely doesn't help things trying to say "it doesn't matter!" The world is just not that simple.
I myself have an emotional negative. I've become tired of being preached to by people who swear 'things work this way' but yet are completely ignoring the facts of the world around us. This gears a lot of my gusto, but I make my number one priority to be accurate, factual, and hopefully share what I've learned so that someone smarter than myself might one day recall what I've shared and piece together more of the puzzles around us.
If we're going to be adults, and have a conversation about the best salts, lithium content is a valid tangent. Even confirmed by one of the most educated amongst us with the reference I posted above as that was part of their basis for choosing one salt over another. (feel free to find out who that was; again, perhaps Google/bing can help you)
Oh, and your comments about 'people breed just fine with RC/IO.....etc'
Ok, why is it only now blue tangs have been bred? How about the THOUSANDS of other fish that have not been successfully bred? Of course we cannot account for every single attempt, nor their water source, or even the other variables. But to say people breed fine with them, is probably .001% of all situations. Again, geared by emotion in defending your choice in salt. (at least the probability is definitely against you being unbiased)
Not trying to be a jerk, but it irks me when people confuse opinions with facts. I know it's hard, even I find myself doing it from time to time, and I'm one of the most logical people I've ever met. :)