The SQ of the s/w based up-sampling really depends on the DAC and how its designed.
For some DACs, like PS Audio, the s/w up-sampling is just redundant (you are doing up-sampling twice), while for some it kills the SQ, like the Dave and for some it benefits. For DACs that have an internal SRC, s/w based up-sampling can have excellent result if there is a way to bypass it. For DACs if they have an excellent implementation of SRC, like DS or Dave or as Jim suggested in the above post with his Rossini, up-sampling yields no additional benefit and can be detrimental to SQ. So its not necessary that up-sampling in Roon (or other s/w) is required or necessary always.
While s/w based up-sampling can have great results and one can easily choose filters/modulators to their liking with few clicks on a button, it must to used in correct topology - try to isolate the up-sampling server from DAC by not connecting it directly and introduce a high quality streamer in between. This is necessary since up-sampling means high CPU utilization, which means more high freq circuits at play and hence more noise - introducing a streamer will decouple it. In my setup, I use a server and streamer both running Roon - while the server up-samples, the streamer interfaces the DAC is decoupled by optical networking.