Yes, our understanding is provisional and subject to change, but if we reject the notion of objective reality then we reject the notion of knowledge, provisional or not.
May I ask what "thoughts" or "novel approaches" of his do you appreciate? Because talking to a flat Earther can also allow us to "question our deep beliefs" but I don't think that's needed to achieve that same goal, and it can even be counterproductive. And giving people who are intellectually dishonest and/or willfully ignorant a platform and treating them like their worldview is worth considering is an affront to the human condition and perpetuates not only stupid ideas but scientific illiteracy (ie. perpetuates not only erroneous facts but more importantly perpetuates a complete disregard for all the tools we have for properly analysing, interpreting and assessing the worth of any data).
I have a different approach to "giving people who are intellectually dishonest and/or willfully ignorant a platform"...I tend to think that you have to give them an opportunity to speak or have a platform, in order for you to destroy it :)
I appreciate some of the following:
The reason I appreciate some of the things I disagree with is because I find them to be valid arguments. Even though we are no closer to finding "truth".