I do not have a lumin and I use an RME ADI-2 DAC which has a volume management by remote control (DSP inboard) but not manageable by Roon.
On the other hand, I use the Roon autolevel to avoid differences in levels (> 18LUFS, especially with Roon radio)
I asked the question because if Leedh processing was superior in quality to Roon 64b float, it could replace it.
2 things: if the superiority is demonstrated and if Roon … agrees to pay the license. 