are NET Switches worth considering?

I doubt that changes upstream of your streamer will affect SQ.

Your streamer appears to be async USB output only, a good thing, so your DAC is doing all of the buffering and clocking.

The data being processed by your streamer is correct, the TCP connection from your switch has error correction.  The streamer then converts the (probably) compressed FLAC to the true PCM data which is then sent, serially, to the DAC, on request.

The  Bravo SA9227 USB receiver in the DAC converts the serial bit stream to the actual PCM data which is buffered and sent to the DAC chips (8 in parallel!) for conversion, based on the clock in the DAC with zero dependence on timing issues of the input stream.

The only issue then is noise, and looking at reviews your DAC gets good marks for very low noise - I think I saw 119dB down.

I want to thank everyone for their input.  It's amazes me how much experience and knowledge so many of you have in HiFi and in electronics in general. I guess having  a lack of experience makes me credulous, therefore I depend on forums like this. I've made notes and will continue to research this. 

There will always be a deal and an opportunity to buy something, but looking back I should focus on the fundamentals like room treatment before adding more electronics. I actually spent several hours looking at panels and quadratic diffusers and consulting with experts on this matter and I have a plan that I'll be implementing shortly.  But it's so easy to get seduced and sidetracked by all this great stuff in this remarkable hobby! 

@mdalton 

Are you saying that a fibreoptic connection between streamer and DAC eliminates the benefit of a switch?

@fire_water 

Do not buy Phoenix Net Switch or any other LAN devices, they are obsolete now. If you want to experiment, buy a Ethernet Filter with Optical Isolation. This will allow maximum noise reduction without robbing the dynamics. I am using an optical isolation in my system and it was an end game upgrade for me. Check it out, 

https://store.lhy-audio.com/collections/audio-switch/products/lhy-ethernet-filter-with-optical-isolation?variant=44858486882477

@tcutter 

I am.  It’s like living next door to a noisy neighbor.  You can make them an exorbitant offer and buy their house from them, but maybe you should try closing your doors and windows and see if that works first.