fix(corrmatrix): Fix LSB rounding

* the system was lacking precision
* MatrixMult round less bits
* Corrector is only slightly adapted to keep margin on KA control

corr_matrix @ b9c9fb19

-Subproject commit 41535391a29dbd3c5cff4f25cc1d287078c154fa
+Subproject commit b9c9fb193c0e00f7750f91b9bdbd611604b982f0