ebbor, we got chastised the first time for trying to digest wood when we can't digest grains. Yes, we have the experience of the failed project to help us. But I think the minor benefit that eating wood would give us is not worth the added difficulty. We could revise in the functionality later, maybe after we've actually captured a wood-rich region? (Because if we can turn wood (the resource) into even a tiny amount of food (the resource), that would allow us to place so many extra Queens)
If you remove the bit about digesting wood, I'll vote for XEDS.
Throwing spears are a... suboptimal design. First, as has been pointed out, our drones are not designed to throw things. Second, we'd be playing catchup with the League, when we could be focusing on our strengths instead. Third, if it works but requires the Wood resource, we won't see any benefit for many turns.
Fourth, it won't help as much mechanically as you think: it wouldn't be ranged damage- we lack both the visual acuity and throwing power. It would instead fall under the skirmish phase, like their Skirmishers (who throw stuff) do. And we're already dealing damage in the skirmish phase. We don't need help dealing with slaves, we already mow through them like they are blades of grass.