Being a developer myself, I would understand how spawning more monsters typically would generate a higher latency, and the latency on your server is great.
However, I really always dreamt of building a water & lava trap that kills monsters automatically and transfers the loot to me. When walking in the night, it doesn't seem as if there are very many monsters spawning. Can this be changed? And yes, I walked away from any form of player population as far as I could.
Also, do spawners exist in your server? If so, I could find one and use it for my trap idea instead.