Seems like this mod makes Spitters not able to damage trees. Biters can damage trees fine when they run into a forest and get stuck, but Spitters will sit there indefinitely spitting at trees that it cannot destroy. Can confirm that turning this specific mod off allows them to damage the trees and move on.

Edit: Seems like it happens with rocks too. Clip of it happening here: https://streamable.com/1v9zqh

Thanks for bringing this to me attention! This mod uses script from a very old mod to make spitter projectiles blocked by walls, but that code is honestly causing more problems than it is worth. Hopefully I can push an updated version removing that soon.

I hope you keep the spitters blocking walls however, I do like that feature haha

Making that feature toggle-able would be the best solution, like in Combat Mechanics Overhaul :)

I agree! I'm going to add it as a mod option, you'll have to let me know if this update fixes the issue :)

Mod option added!