Good drone controller can make difference in controlling the drone. Flying with precision movement such as in a small space like in the cave, need good precision controller so it doesn’t bump the wall or even crashing in to the wall and making it damage.
Increasing the transmitter power of the controller or drone also increases the control range of the drone. However, it is a common misconception that doubling the power will double the control range. One actually needs to increase the transmission power by 4 times in order to get double the distance. Radio waves propagate in the shape of a sphere, and the power density changes proportionally to the square of the radius.
For example, if you have a 1 Watt transmitter that reaches 1 km, then you would need a 4 Watt transmitter to reach 2km, on the same system. Or course, power is only one of the variables used to calculate how far can a drone fly.
These are controller that you can try. Different type of drone need controller that match the controlling characteristic.