So, I wanted to check that Foliage for any UserAssetData Container and discovered that small field “Component Class”…
So, I created a new Child Class of that FoliageInstancedStaticMeshComponent Class and set it as used Component Class in that Foliage.
After Initializing that Foliage Info, the specific Component gets created and is accessable. Before Initializing that Foliage Info, you will get a nullptr or similar, anyway u cant access the Component before Initializing the FoliageInfo. Now you can set anything you want inside that Child Class and access it in a HitResult from a line trace.