The datasheet only specifies the power supply ripple rejection for 120Hz.
Is there data at higher frequencies (100kHz to 1MHz)?
Is the performance close to chips such as LT3042?
We don't have the data specially for RH1965, but you can use the PSRR of LT1965 as the reference. The bandwidth of RH1965 is lower than that of LT1965, so please add more output capacitance at high frequencies.
LT3042 has ultrahigh PSRR. I would recommend to use this part.