You have 2 options. Do note that most all PCM DACs up/oversample internally. The Yggdrasil is one of these DACs. It does not have a “NOS” (non-oversampling) mode.
baldr across the intertubewebnets is Mike Moffat. He is one of the founders and does the “digital” side of Schiit. The Yggdrasil employs something he calls the mega combo burrito. Do a search for baldr and “mega combo burrito”. He’s talked about it extensively and why he feels its one of the finest DAC filters in over 20 years. Leave things the way you have it and you’ll be utilizing this mega combo burrito.
The other option… set Roon to upsample everything to the highest resolution of the DAC which is 24/192. I believe, since you are already at the “native” frequency of the DAC, bypasses the mega combo burrito. Then you’re, effectively, using Roon to do the upsampling required by the DAC.
What you prefer is of personal preference. There is no “right” answer other than you subscribing to the reasons Moffat constructed the mega combo burrito in the first place.
I, personally, convert to PCM, no MQA, fixed volume, rsync 1500 (to give the muting relays a chance to be done with the resolution change, 192, 24, enable MQA core decoder, buffer is dependent on your network not the DAC, down mix as needed.
Thanks very much everyone for the quick feedback. Sounds like I should probably experiment a bit with upsampling to 192 pre-yggy vs letting all upsampling happen in the Schiit. System is sounding great already though, so probably no need to mess with it too much!