...it's a possible problem for performance and savefile size.

I would be glad if picked up factory reseted it's content. I'm thinking about modifing the mod so when factory is picked up all it's content is destroyed (literaly GONE) and surface also destroyed. That should be easy.

Better option would be similar to picking up any other factorio entity (giving it's content into player inventory and cancel picking up if player doesn't have enough space). I just didn't look into it, if it is even possible.

Anyway some way to config pick up behaviour would be nice.

The reason to not destroy everything when you pick up the factory is so that you can move them. Which, IMHO is a good thing.

I would instead recommend a new item to "clear" a factory, destroying everything inside as well as the surface, and also verifying that the surface is created on fist entrance (not on placement)

NOTE: this response is mainly meant for the Mod Dev, and not the OP specifically. Though this might explain to the OP why it is the way it is.

• Monk

I take back my words about destroying surfaces.
First of all, Atria, it's bad idea to destroy surface when factory is picked up, because it's feature is ability to be re-moved (picked up and placed again).
At second, I've found that it's impossible to destroy surface: "Surfaces can only be created through the API and can not be deleted." proof
At third, it's not the worst idea to clean the surface of the factory if it was destroyed - only in this case.

.13 and up allow surfaces to be deleted with game.delete_surface. The can't delete message is .12 stuff :)

I thought about writing a "factory" management mod then realized I have too much going on right now :)