Meta blocks

[Vintagebob]

Hello,

I wonder for what the meta blocks "Pathway" and "Underground" are usefull. The "Filler" one fills structures with air, when they are generated, and the "Spawner" spawns entities. But what do the "Pathway" and the "Underground"?

[Conquest of Blocks]

As far as i remember, pathway tells entities that there is a entrance (e.g. into a building) they can use and underground may tell the game that the area is underground (e.g. for knowing to play underground sounds). But i could be wrong.

[jabes]

Can someone explain to me what the "begin spawning only after imported" checkbox means on the Spawner block? Do I have to do something other than filling out all the parameters in the block menu to spawn entities? I am trying to add a boar spwn close to my base. 

 

I have attached a photo of the menu for context.