The squeezeLPP function performs unnecessary absorption and permutation operations on the state matrix. These operations are redundant because the state commitments already contain this information. The function could be simplified by directly using the post-state matrix.
Instead of absorbing and permuting the input bytes, the function should take the state matrix after absorption of the post-state as an input. It should then verify this matrix against the _postState.stateCommitment before performing the squeeze operation. 
As per the inline comments:
So this also goes for the final state commitment which could be used directly.
