When I attempt to use these assets in Unreal Engine 4 they appear very small in the menu, and when I spawn them in I have to drag them out for about 30 seconds before they are even some what useable, please help
I already answered this question from you in the comments of the Modular Terrain Pack. You have to scale them up 100 times when using them in unreal.
The models are based on the cm scale, not the m scale. They work fine for other engines like Neoaxis and Platinum Arts Sandbox, and other 3d engines that use the cm scale.