Filler lots will grow as a vacant lot with a random trees/bushes/props on it instead of an actual building. This should make your city look a bit less dense and a lot more variety to your neighborhoods. Residential filler lots will have props typical of a side yard or vacant lot. Commercial filler lots will have props typical of a parking lot, or construction site. Level 1 filler lots will look appropriate for Level 1 neighborhoods. Level 5 filler lots will look appropriate for Level 5 neighborhoods, etc.The Probability Changer mod was used to vary the frequency at which each props grows. Each time this lot grows, it will take on a new look depending on which trees and props grow with the base lot. The user does not need to install the Probability Changer mod to make use of this feature.Most of the props and trees are default. However, I am also pulling from a collection of frame-rate/memory friendly props and trees, which you can subscribe to using the link below. If you don't subscribe to this collection, it will still work, but there will be a few props/trees missing.Check out the More Better Buildings collection for more assets such as this.