Using LMS7002m as a modulator

In https://wiki.myriadrf.org/LimeMicro:LMS7002M_Datasheet#Numerically-controlled_oscillator
it says : therefore NCOs can be modulated by direct symbol insertion. Up to 16FSK or 16PSK modulations are supported.
Has anybody tried to generate modulation like QPSK, also since it is done by SPI how is the correct timing ofshifting the phases achieved?