The RNDI-8 is just a set of 8 separate DIs, each with its active transformer (activated via 48V phantom power switch) and IN and THRU inputs, stacked in a single rack unit space.
Using it as my audio signal summing hub. A bit of “analogue” flavor by utilizing the Rupert Neve Designs RNDI-8 and pass everything through it now: On the way in AND on the way OUT (meaning that ALSO the outputs of my other signal processors enter an IN port of the RNDI-8). Kind of like an audio signal summing hub on the way in, making it the centrehub and the first station in which all my unbalanced audio signals from instruments, preamps and effect pedals go before hitting my audio interface.