Whereas, for an instamine or stealth proof-of-work mining launch where a significant portion of the money supply is mined over a very short period of time mostly by the developers group (and their insider friends), theres no significant competition and thus the developers (and friends) mine the tokens at nearly zero cost (relatively speaking to the price they sell them for), and thus a very significant portion of the money supply has been effectively pre-mined at nearly zero cost by the developers who the investors expectation-of-profit depends on. Thus this is economically equivalent to an ICO and thus those tokens are effectively ICO-issued tokens under the Howey Tests criteria. This is what transpired for Dash, Steem, and Bytecoin. In Bytecoins case, the stealth mine may have been over a long period of time, because afaik it was not publicly announced for up to year from the date of the genesis block.
My only "objection" is that I don't think there was an "instamine" or "stealth proof-of-work mining" in Steem, there was the [ANN] thread, and there was the code available for everyone. No matter how much easy the mining process could have been, there would always be some people that could not mine at all. If we make the claim that Steem was "premined" because people could not mine it if they didn't have a degree in IT then we can also make the claim that most coins are also "premined" because they require at least some basic IT knowledge, lets also not forget those that don't even own a pc, everything must seem "premined" to them. What I'm trying to say is... where do we draw the red line when we talk about "premine" based on how "difficult" is something to mine?
Imo, it's too far fetched, that's all.