It is the single thread performance of the NUC you need to look at
I prepared a comparison table here Intel NUC - Roon Rock - only for TIDAL - #8 by simon_pepper
This covers from the NUC5i3, NUC7i3 (as per a Nucleus), NUC7i7 (both the 2 core & 4 core version, the later used in Rev B Nucleus+), NUC10 i3, i5 & i7, and with the best single thread performance the NUC8i7 but at a cost of 28W TDP over the others 15W TDP
In a past Benchmark I was able to use a NUC5i3 to perform DSD256 upsampling, while sustaining playback in other zones, indicating the DSP is core bound.
For DSD512 upsampling, either the use of 2 core Sigmar Delta processing or you need to use a Desktop based CPU with a greater single thread performance.