(1) Nothing in this title shall be construed to discourage employers from:
(a) Adopting or retaining leave policies more generous than any policies that comply with the requirements under this title; or
(b) Making supplemental benefit payments as provided under RCW
50A.15.060 to an employee on paid family or medical leave.
(2) Any agreement by an individual to waive, release, or commute his or her rights under this title is void as against public policy.
(3) After January 1, 2020, subject to *RCW
50A.05.090, an employee's rights under this title may not be diminished by a collective bargaining agreement or employer policy.