@Jessica Smith yeah that's a totally fair concern, and you're right that the 50km figure is drone-to-drone with both units elevated and zero ground reflections eating into the signal — ground-to-ground is the 5km spec, which is the more relevant baseline for fixed sensor nodes on rolling terrain.
For NLOS with tree lines and low ridges, the honest answer is "it depends a lot" but you're probably looking at somewhere in the 40-70% range reduction depending on foliage density and how much of the ridge is actually blocking the Fresnel zone rather than just the line of sight. Dense wet vegetation is actually worse than a hard ridge in a lot of cases because it absorbs rather than just diffracts. A dry scrubby tree line in summer is more forgiving than you'd think, especially if your nodes have any elevation at all — even mounting them a meter or two higher on a post makes a real difference at 2.4GHz.
For your farmland layout specifically, I'd think about it less as "will it reach" and more as "can I add a relay node on that high point." The MultiNav Pro+ works in mesh configurations through the app, so if you've got a hilltop or even a slightly elevated point between your clusters, you can use one node as a repeater and effectively chain the range. That's probably the more reliable architecture for broken terrain than betting on raw NLOS penetration anyway.
If you want to share roughly what distances you're working with between nodes, I can give you a better sense of whether you're well within margin or pushing it.
