I've noticed that when I have multiple structures with the same spawnRate, they tend to all spawn very close to each other (which causes massive slowdowns when generating/loading chunks where these structures are located). I think this could be solved by handling spawn rates in a way more similar to how recurrent complex does it. In Recurrent Complex, structures are assigned a category and weight in a JSON file. Each category would have a spawn rate associated with it. Then instead of spawning each structure every n chunks, you select 1 structure from a given category every n chunks, using weights for individual structures to determine rarity within a given category. In Reccurrent Complex, the categories are predefined, but I think it would be better if they were user defined in the config file.