Solution
Unfortunately, no.
Different I/Q rates cannot be configured. Even if it is physically separated, if different I/Q rates to be set, the application will be prompting an error after the generations as below.
Setting different sample rates for the two channels require different write size for each channel, meaning that we will be using single channel write for each channel compare to use 2D array as channel input. This is not supported by NI-USRP API. It will throw the error below.