Game lags in "non-populated" areas more than "built" areas?

For some weird reason my game lags more when i’m in the middle of a road on a empty field than when I’m in a area with actual “stuff”, in the latest experimental version. I have noticed some input lag in the new version compared to the stable (around a few half seconds or so) but that’s probably to be expected with unstable versions that have yet to be optimized, especially with the more it is added to. However for some absurd reason I noticed that the lag gets worse in areas with nothing going on. I’ve checked the map to see if there are any resource intensive things nearby like triffids or fungi, but the nearest thing that may cause lag is a ant nest which is half a overmap away. Other than that the place is literally empty for miles, without even a dead patch of grass or something. And even when I teleport to someplace I know has “stuff” like a hotel, that significant lag vanishes.
What’s going on here? Any way I can fix this?
I can (relatively) deal with the frequent glitches or crashes, but the lag is really killing my motivation to continue with the unstable which I really want to continue with because of the added content.

I’m also noticing a lot of lag in the most recent build.