Apple does not allow users to manually adjust roaming aggressiveness. Apple devices use a proprietary algorithm that dynamically adjusts based on motion co-processors and signal history. Generally, macOS is optimized for aggressiveness. You cannot change this.
This article provides an exhaustive answer to "what is roaming aggressiveness in WiFi?" We will cover its definition, how it works, when to adjust it, and step-by-step guides for optimizing it on your devices. what is roaming aggressiveness in wifi