Suggestions

mobs after server reset stay and don't de-spawn

Not sure if every server does this with the mobs spawned by spawners, but i afked for 6+ hours to increase the mob amount that i get. There were thousands of blazes and zombie pigmen but after reset they all disappeared. Iron golems on the other hand don't de-spawn. Don't know why, but if possible can you allow the mobs to stay after reset.