I do suppose Starsector is a pretty extreme example of where the small tester group idea might break - with releases 6 months apart (or even longer in this particular case with 0.8a), there is a distinct possibility you could get burned out. Although hey, it took me nearly two years of both modding and game development on the same project every day before I nearly had a mental breakdown and needed a break - take that for what it's worth, I suppose. As for the signal-to-noise being low: if you organize it well enough (for example, using Trello, which I've used in the past for testing games), it's not too much of an issue. But hey, you never know it's potential until you try it. Maybe for a slightly less ground-shattering update, it might be worth experimenting with.
I was actually a bit shocked at how barren it was (and worried "oh god this is going to be the most boring blog post ever").
It was a wonderful blog post David! You got to show off a lot of stuff we hadn't seen yet, especially some of the system generation and exploration from the player's perspective. Even if the trip turned out to be boring, we would have gotten to see a lot of awesome stuff we haven't seen before. Luckily, it wasn't a boring trip, and we all got to see some extra-juicy stuff.