AD9684: ADC virtual converter mapping

Some ADCs such as the AD9684 have 4x DDC with virtual converter mapping.

If the AD9684 ADC has two physical channels and I enable 2 virtual converters in IQ mode, this should result in 4 individual voltage outputs for libiio and appear as voltage0, voltage1, voltage2 and voltage3 in iio-oscilloscope.

I would like to know where the virtual converter mapping done (e.g. in HDL or the Linux iio driver level) to make the invidual I and Q channel voltages available for iio-oscilloscope.

If I look at the HDL for a comparable ADC part, such as the AD9680 JESD204B part, in both the HDL and the linux iio driver, only 2 physical channels are enabled.

I'd like to know how data will be streamed and displayed on iio-oscilloscope if I enabled 2 DDC in complex mode, to make 4 voltage ouputs voltage0, voltage1, voltage2 and voltage3 to appear.

Updated title and post.
[edited by: elvisjohndowson at 2:40 PM (GMT -4) on 12 Sep 2020]