Correlation matrices C for the highest-f_sv light curve regression models obtained for KIC011971405 and KIC012258330. The strategies that correspond to these light curve regression models are listed in the ‘Strategy’ columns in Tables 2 and 3. Equation (A.4) delivers the explicit expressions used to compute the correlations within each block, which are displayed at the locations specified in Sect. A.4. The change in darkness between the upper and lower triangular part of each matrix is aesthetic.