My #1 suggestion for a podcast guest would be Naval Ravikant. He seems like a very clear and thoughtful communicator both on Twitter and in the two podcast episodes I've heard him on (one crypto related and one on other topics).
I looked back in the podcast feed and it looks like Tuur Demeester was on in 2015. He's my other suggestion -though since you've already had him on- it'd be a repeat. Not a bad thing of course!
Thanks for the follow! I'm queuing up some back episodes of LE to listen to on my walks.