I saw this from other sites. Hopes it helps:
For those using mods who are frustrated with the "settlement"
You cannot use split of free crafting there.
You can split regular items like planks, wire, bolts, etc.
But the special items, which take forever to get like asbestos, antennas, screws, etc. You must get those the old fashioned way and cannot use split on them. Plus you have to start the game with cheats disabled to do the building.