Do you have dual rates or flight mode in your radio programming? If so, lower your EPA settings for valves & swing so it makes your stick throw on the gimbles less sensitive & you will have much finer control while trying to change attachments. Then you can switch to a different rate of throw for digging.
On airplane radios it's usually just aileron, eleveron & rudder that have dual rates, and with Fmode you can change throttle curve per mode to achieve the same characteristics as dual rates.
When I 1st started rc excavator in 2001, I operated my model much like the way you are now. Something that was said to me by an experienced machine operator after showing him my model, "what separates the best from the rest is how much the tracks move around while digging at full capacity of the machine".
I don't wish to be mean or rude, but rather be helpful to guide you to operate your model with greater finesse & professionalism, it makes watching videos of what you're doing more enjoyable.