Your second would be the debate between Furman and Kelton on the Ezra Klein podcast, as I said.
I'll dig up a third cite. Like, one of the things in my head is the Kelton vs. Krugman argument, which I read on Krugman's blog, but that's not the best cite, since you're getting Kelton secondhand through Krugman there.
Happy to help. If you'd like to help too, you could cite a source that says MMT'ers feel like inflation doesn't matter.