With all respect and due deference to @sns and his demonstrated expertise with optimizing the Mac Mini, the Mac Mini is far from an optimal solution as either a server or a streamer today. It was a wonderful solution 10 years ago which "sucked less" than other options at the time. But that shouldn't be your standard.
I used to be be where you are 5ish years ago. I bought a Nucleus Plus with ssd to replace the mac mini, which improved both the server and the usb output, which were both more quiet than Mac Mini. I then purchased an Innuos Zenith Mk3 which improved (and simplified) everything. Considerably. As a server, it was quieter than the Nucleus Plus (which was quieter than the mac mini) and very stable. In fact, other than software updates, it never required rebooting. As a renderer, it actually makes the Mac Mini seem quite primitive because of the improved usb output.
I have since sold the Innuos to make room for a next level server/streamer but there are many options out there that leave the Mac Mini behind and improve upon the Nucleus and other similar nuc's.
@sns I'm not sure I agree with your passing dismissal of "audiophile network switches". It would be great to know what you tried and in what context. I have recently experienced a switch (its hardly cost effective) which elevated everything about my musical presentation. Not by a little. In fact, it was kind of embarrassing how much of the music I wasn't hearing. The switch improved the musical presentation immensely. An ethernet filter improved it a great deal more upon the previous improvements.
You can get a lot of the way there for very little money but the last 10% gets very expensive. @bigwave1 there are so many wonderful, stable and no-longer-tweaky solutions available today. Go for simple, high quality solutions. While I recognize that many people enjoy three or four different "decrapifiers", converters, stacks of linear power supplies, etc, etc its just not necessary today if the goal is exceptional sound rather than a Rube Goldberg style mousetrap.