If you want just bridges, you don't need this mod.
Edit demo-item.lua
line 15
condition = { "water-tile" }

change it to condition = { "floor-layer" }

And voila. No need to restart/regenerate map.

Just can't.
They're coming like river after nuke bombarding.

Maybe slightly offtopic, but... Is there any method to don't stuck with low FPS when too many enemies became angered and entity_update takes 48 of 60 fps?

12.15 and bob's mods and some other.