How does the extraction work in a simple syrup? That doesn't make much sense since THC is mostly alcohol or fat soluble. Never heard of that. And yeah, you want a gastrique slow and low, but that doesn't mean that THC will end up getting absorbed into it (as far as I'm aware anyway). You have a link for the simple syrup process/example?

People can't even seem to get the basic extraction processes down, much less ones not involving fat/alcohol... have you actually tried a simple syrup and noted the potency? Color me skeptical of that one. The only way I think a gastrique-like thing would work is if you used a glycerin tincture in it.