Tremors are usually harmonic induced, gimbal motor deficiencies, or PID issues. The harmonics can be dealt with if the frequency can be determined and dampers designed for that frequency used on the gimbal. If a lens is too heavy or its center of gravity is to far from the center of the gimbal, inadequately sized gimbal actuators will shudder trying to stabilize the weight. Same thing happens if voltage is too low when fast PID’s are set up.
When they are designed and built right these little gimbals are software optimized for but a single lens application. Any change in weight or lever arm from OEM state will destabilize them.
When we consider these systems have been designed around what I call the “law of minimums”, meaning the smallest, lightest, cheapest component available for any given portion of the system, we might figure the gimbals are already being pushed to the edge of their capabilities.