My experiences suggest that the AURALiC app produces better sound than Roon within the AURALiC product line. I ran into several issues in Roon - the biggest offenders being a hot/clipped signal and marginalized soundstage. When I used a different streamer, the signal was not clipped so the optimization between Roon and AURALiC might not be 100% there yet.
I have no experience with Aurender and my point above is that if you do go with AURALiC, I'd suggest not letting Roon integration be the deciding factor if SQ is your overall goal. The Lightning DS app is very good both functionally and sound-wise. It does have a few quirks like most apps, but its still very solid.