@jussi_laako - Thank you, that is really useful. Yes for me 100% having everything checked works better. ASDM7EC did not work with them greyed out and it works perfectly with everything checked. When I rebuild my Ryzen 5 2600 I will at least try ASDM7EC with the same settings - am interested to see if it works.
Looking at W10 task manager only 4 cores are being fully utilised. Would DSD512 be any more a realistic goal if more cores were thrown at the problem or does it not scale like that? I am at the limits of my technical understanding of how all this works as it is 
@dabassgoesboomboom - Whilst I downloaded the 24/192 version of Hoff Ensemble - Innocence, Roon is showing it as 24/176.4. Nonetheless it plays absolutely fine at DSD256, Poly-Sinc-EXT2, DSD256. And sounds blooming lovely too.
@DancingSea - Agree to an extent however having now set it up I am wondering just why I struggled with it. Perhaps we overcomplicate things when in fact it could not be simpler. Click a button to enable web services, look up your computer’s IP address and add it to Roon and that’s it. It is, essentially, as easy as adding Qobuz or Tidal.
But yes, people (including me and I consider myself to be very IT literate) still struggle with it! That said I am now comfortable I could talk someone through the initial set up but I’ll admit the science behind how the different filters work and the effect they have is a little beyond my understanding. I just know what sounds good to me…