And as if by magic, John Davis suddenly appeared.
I'll get in first. The society is going through a period of transition. And by transition I mean its crumbling because no one looks after it. This means that most of the flat earthers keep a low profile and have stopped posting altogether and what you have left are a bunch of trolls that will write almost anything to the detriment of the society. It is likely you will have to wait some time before one of the mouth pieces of the society raise their heads to claim their authority on the subject matter.
In short you are going to find it hard to get a decent interview. I wouldn't even entertain an interview with anyone with under 3000 posts.
Your best bet for an interview IMHO is
Tom Bishop. He knows everything there is to know about flat earth theory and he is an interesting character at the very least - if you are lucky he may oblige. The Round Earthers here hate him, but that should give you some idea of how formidable he can be in debate. He also rarely does interviews so yours wouldn't be like all the Shenton/Davis interviews that you can google.
Inb4trolls screaming about trolls and that everyone is a liar and fake and blah blah blah.