I suppose one scenario in which you might want to add a streamer without a DAC is if you want your Nucleus to be in a separate room, and you want to use the Tambaqui as a USB DAC (instead of connecting it by ethernet). In that case, you might consider one of the Sonore Rendu products (such as the ultraRendu). That's assuming you don't need the device to support, separately from Roon, a streaming service such as Tidal.