Technical support does not cover modifications of the control source code. That means you are free to modify it as you want, however, we will not be able to provide assistance for the modified product.
That said RadChart does not offer interpolation. By that I mean it will not combine 10 data points into 1 or vice versa. You will have to generate your series items manually. That doesn't require changing the source code of the control.
I hope this clears things a bit.
the Telerik team