The foliage spawning tool is meant to be used to create organic looking worlds, it is definitely not thought for voxel based worlds like Minecraft. I am afraid you will have to build a customer spawning system which aligns your blocks to a 3D grid.
Many people have worked on re-creating a Minecraft-like interaction in UE4. This is a particularly good series, but it is C++ based and right now still unfinished:
Have also a look at this Forum thread:
You may find useful tips on how to implement your game.
Last but not least, have a look here: https://sellfy.com/p/Ho2F/
I don’t know how good this toolkit is and I never used it myself. Make sure you contact the author to ask all your question before deciding to purchase it.
Good luck with your project!