New features and notable changes:
Passing values in C++ as a template arguments has some inflexibilities. For example, if template function has been wrapped into a functor class, there are no ways to pass some value as a template argument.
Digital biquad filters and biquad filter design functions are implemented in the KFR framework starting from the first version.
Biquad algorithm uses the Transposed Direct Form II which reduces the quantization errors in the floating point calculations.