I listened to their podcast. They had a rather informative overview on the style. The original owner of the Schlenkerla was lame, one leg longer than the other that made him have a wobbling gait. That was missed, but it was also thought, that he was often intoxicated.
The guys thought about it'd be cool to have a fire while tasting smoked beers. Would be cool, is a monumental mistake in my opinion. How can you sense the taste and smell of smoke in a beer if you're fanning smoke from a fire away from yourself. That's no different than trying to taste test pasta sauces that have varying amounts of garlic in them as you're pan frying garlic and onions in oil.
They might have had an old beer based on where they bought it, the smoke flavor might have been diminished, how could one tell with all the smoke off of that fire? Especially if they're not familiar with the style.
One thing that was obvious was that none of them own a smoker, as they were ignorant about wood and smoking. I think the main guy, leading the discussion got it though as to the process for the making of smoked malt and its impact to the beer. He's appeared to have no experience with smoking meats. I will say beech is not that common, as I never saw it in Iowa or in my location in central Illinois. It's not prevalent in Chicago either.
I think the obvious use or reason for beach was missed. It's readily available in that area of Germany, Franconia, or Bamberg. So they use it to fire the kilns when malting.
They referenced Budweiser and it's use, but none of them knew why its used. I'm just as guilty so I read up on it. It's use has to come from the desire to help clear the yeast. It's like a false bottom in the lager tank.
https://beerandbrewing.com/beechwood-aging/
Sam Caligione - Head brewer for Dogfishhead sites it's for this above reason too in ale aging. The yeast settles on the floating wood chips.