Modeling polarized X-ray signals has been implemented and examples added for simulating polarized pulses (Stokes parameters) using a couple of different atmosphere options. Support for polarized likelihood calculation has also been included. In addition, new integrators (with and without polarimetry) have been implemented to allow atmosphere interpolations with 5 parameters to be performed in 2 steps. See further details reported in https://github.com/xpsi-group/xpsi/blob/main/CHANGELOG.rst.