Doubts and questions and problems about placed_feature in jisawg

1.Can placed features be generated in structures?
2.If the placed_feature has a filter to search for grass blocks to generate the feature and the structure does indeed have these blocks, shouldn't it be generated?
3.If the structure is generated in raw_generation and the placed_feature is in the last part of features in the biome, shouldn't it be generated?
I have a problem... in my custom dimension, only floating structures like gardens are generated... it happens that I want trees to be generated naturally but I can't... and when I remove the block filter it works... but everywhere...