Now, if the spreading ores could damage machines and such, except a speciallized wall or mining machine you could make some spreading swamp which could be a threat to the factory

probably see if you could use this mod along with dangoreus mod? "Great! Now i have to line the walls of my base with not only laser turret but large area miners as well!"

or you could put up a speciallized resistance wall.
or some miners which will pump speciallized fluid into the ground to stop the spread.

after all the world out there is dangerous

and the factory is never satisfied......

Well It seems they now do damage buildings and such

You are need the https://mods.factorio.com/mod/dont-build-on-ores for better working