I must admit I was wrong about my approach to Roon. Thanks to
@drkrack and
@Phew, I read up on how to go about integrating it into my chain to maximise both sound and UI. Apart from wanting to give Roon one last shot and determining if I was extracting the most out of it, my other concerns were a) How much I'd have to invest if I got hold of a dedicated server, which would then influence b) If I could hold on to my MacMini for computing, downloads etc.
@drkrack put me in touch with a techie in Pune who had an Intel NUC for sale (Lenovo P330; i3800 with 16 GB RAM and 256 GB SSD, at 10.5K); he even asked the guy to install Roon ROCK (it's a fairly simple process, listed here:
https://help.roonlabs.com/portal/en/kb/articles/rock-install-guide) before shipping the unit. All I had to do was run a few updates, and the thing was good to go.
I won't go into the UI, because it's almost universally accepted that Roon has it nailed down. It was performance that mattered. Straight of, the sound characteristics were far superior to those that I'd heard with the MacMini. Second, and more importantly, they were marginally better than with the Lumin control software.
I wouldn't spend a lakh+ to get hold of a Roon Nucleus (or any other comparable, built-for-Roon server), but the rig I now have is more than worth it. This one's a keeper.