I only don't think he's a troll because the non-illusion options seem just as wild to me. I think it's fair to say we've made almost zero progress on how sensations/experience physically work, and there's not much more room to look. For one critique of the progress toward a computational theory of mind, Tim Maudlin (philosopher of physics) says we are no closer today than thinking water and trough computation could get us to explaining how toothaches feel.
As for how illusions occur and from what things, it does hardly seem possible. But the alternatives are hardly better.
Total agreement on the fact that we are as clueless as it gets to explain emergence of experience. That's why I think that the only reasonable avenue forward is to try and take experience as a fundamental building block. We are going through our age's copernican revolution.
The illusionism argument is ridiculous because an illusion is still experienced (the very fact we are talking about it is proof), so at best it is circular reasoning. Probably it's woo-enough to be taken seriously by some :)
As for how illusions occur and from what things, it does hardly seem possible. But the alternatives are hardly better.