4017 IC switch matrix controller and library. Up to 100 switches with 3 pins!

Your are right.
To your example using one 4017 it is obvious how you done it.
But if you see the matrix example of the first edn article 4x3_matrix_2_4017

both reset are connected to outputs of 4017. If library can handle this i ll give a try connect both reset to arduino output.

Thank you for your fast answer.