I have two features on my mind for our use case of the RadialBargraph but it makes sense for all Gauge classes:
If the value is greater than the maximum value display a '+' as a suffix on the value label. For example: If '50' is the maximum value and the current value is '100' the value label should show '50+', to indicate that there is even more than the Gauge displays.
Add a logarithmic scale: We use the RadialBargraph to display the number of currently active events. Usually it shows a value between 0 and 20. But in some cases (long running events) this number can increase to a few hundred. Without a logarithmic scale I have to choose between two things: A small scale which does not display the bigger values or a large scale where the smaller values are barely visible.