On the one hand, I absolutely love that the devs are "drilling down" into how the deeper strategic and development decisions are being rolled out. It's one thing to get a DT like we did earlier in the month where they lay out their thinking; but another thing altogether to see that in practice (e.g. seeing how the lighting improvements actually go towards that goal of bringing hearthling interaction with the world to life.)
On the other hand, though, more variety is always nice. These 'deep dives' may not be so interesting for people who are more keen on playing the game than on watching its development journey unfold; and while it's hard to show off unfinished features in a meaningful way I'm sure there's a chance for some other kind of discussion... a way to get players talking about something not directly linked to upcoming features, but still contributing to that broad goal of improving the feel of the game.
One example which comes to mind would be a DT dedicated to nailing down some lore. Whether it's the history of the world of Hearth, info about a specific faction, or even just crafting the story of a particular hearthling, I'm sure that plenty of us would be keen to see the narrative side of the game explored a little further.
It's probably not a good time for another DT dedicated to (visual) art, but that's something to keep in mind for the future too.
A showcase of player builds would be a cool DT for a "slow week", or rather, a week where everyone is super busy working on things that aren't ready to be shown yet.
And one I'd personally love to see would be a compilation of amusing in-game sitautions, bugs, and general unexpected/quirky gameplay; in the style of Rose Belltower's legendary night watch. That's another one the community could get involved in, sending in screencaps or videos; but it's also a chance for the team to show off the quirks of gamedev and how old things sometimes interact weirdly with the new stuff. I'm sure the work on overhauling water must have yielded a few such funny moments.