Help me shop: Optimising Roon with a Dac

Very much a Roon noob still but have been getting fantastic advice from this forum! I have a NUC8i7 on the way with 8GB ram and good Samsung EVO m.2 256GB storage for the OS etc. Will mount my small music collection via USB SSD. The NUC will be in my home office connected via Ethernet to the rest of the rig in the living room. I’m now researching for an endpoint streamer and a DAC.
My questions are:
(1) Do I need to get eg an Allo USbridge or will a simple Pi4 or 3 running Ropiee in a case do? I’m getting very conflicting info re the quality of the improved USB of the Pi4 vs the quieter 3+and do I need the USBridge or not to feed the DAC or just go direct to the DAC?
(2) THE DACs I’m likely to consider are either the Yggdrasil or the Giessler Fein II. Both are not Roon ready. I would like to understand whether the functionality of Roon is diminished because it can’t “see” the DAC and tune itself accordingly as it can only see the Pi? Will I get the best from such “invisible” DACs? (Fyi My integrated amp is a Rogue Audio Cronus Magnum 2, my speakers are KEF LS50 and dual REL T9i for a 2.2 system.)

What Roon cannot determine from a Roon tested device, it can have reported via USB and you can intervene manually with config. Roon Testing is an assurance thing. It doesn’t impact functionality so long as the DAC manufacturer states that its USB works to Linux OS’s.

Hi Henry, thanks for helping again. Could you expand on what you mean by “it can have reported via USB”? What will report to Roon the optimum capabilities of the DAC?

USB isn’t blind. It will tell Roon what it is and report back it’s capabilities. For instance if it cannot do DSD, Roon shouldn’t offer you DSD as a configurable option. Roon should be able to glean intimate knowledge of the USB capabilities wether it is tested or not so long as the USB input meets the appropriate specification (audio class 2 and Linux). That bit is a question for your DAC manufacturer.

That’s very useful and informative. I’ll check with the DAC designer, thank you very much.