I don't think he would be interested in the Sea of Stars to begin with, because his idea is that some people desire to go back to it rather than be in Ryslig, so he wants to snip their connection to Ryslig. Researching and finding that yes, it IS the Fog God that ties them only to Ryslig due to her blind snatch (and his desire to Do No Harm, even to her) will eventually have his research turn to the Sea of Stars.

He will desire to know what exactly the Sea is, and how it pertains to their own worlds (which might come up with nothing, I'm sure), how the Fog can dip into it, whether it's noted anywhere that the Day or Night could as well, how to recall people to it if that's what they desire (some find the thought of unawareness much better than consciously being aware of what they're doing), and if it's more of a living entity, in the end, how to sever the connection to IT so people can go back home. He'd also look into people who might have stared at the Stars for too long, what they feel because he can't see them, debate on whether the Stars might be eyes, look into info for that, etc.

And yes! I have plans to make it into a player plot, once I have enough information, and have come up with potential backlash and etc. But I don't want to commit anything down yet, obviously!