Fiber Optic isolation causing listening fatigue

The outcome varies. There’s no guarantee any of the tweaks will result in improvement. 
I owned Aurender n200 and adding the converters resulted in more of an analytical type of sound. The network implementation in these streamers is pretty robust. They reveal differences in Ethernet cables and that’s purely from a tone and sonic signature perspective. Noise is not so much an issue and the fiber conversion isn’t really necessary. 
 

Now, using my current streamer as an example, which is a network card built into the Meitner DAC, it is more sensitive and can benefit from additional filtering. I still don’t use fiber there but using a WW Ethernet cable with integrated filtering into switch and then a high quality etherbet cable into network card makes a very audible difference. 
Same applies to Roon Nucleus One - it can benefit from filtering. 
 

Trying what works best is the only way to know. 

Some of this stuff I’ve read on here is hard to believe

Well, I’m not sure what the specific issue is but this setup is a no go. This morning I listened to Miles Davis’s "Agitation." After Tony Williams’ drum solo, Miles comes in with a stacatto muted trumpet solo. I listened first with the fiber optic cable in place. The drum solo sounded out of tonal balance, emphasizing the higher frequencies of the cymbals. When Miles began playing many of the trumpet notes were just too hot. I had to turn it down. I then removed the cable and things sounded more natural again. It was a good experiement, but I’m not ready to start throwing more money at this. Down the road I may consider an ethernet filter or a better fiber converter. Or, I may just stop worrying and enjoy my stereo as is. It is pretty sweet, and I’m not sure a problem exists. I was just curious what level of detail I could conjure.

I have had the same thing happen every time I upgraded to reduce noise.  There are more fine details and information to process and I can detect.  I don’t see this as a function of fiber, but just less noise and more detail.  I think this causes the effect you mention because there is more detail for your brain to process and you are in critical listening mode after only a short time from making this change.  Having more info for the ears to take in and the brain to process is tiring.  IMO, this is the effect you are feeling.  I suggest you give it some time to get use to it, and try to listen to the overall music, without focus on the details or any one aspect - e.g not in analytical mode.  I think over time, you will get comfortable with it and really enjoy the added details, which often adds to the realism.  I prefer to listen for weeks or a month before reaching any conclusions.  

@brbrock No, yes, kind of.

Using the TP WR902Ac as a CLIENT. It is connected to the my router via WiFi and in client mode it isolated the network to this singular device. It is connected to my Zenith via Ethernet cable. This eliminates the need for the Sonore Optical Modules I was using coming out of my Edisoncreation Silent Switch.

Router>WR902AC>Silent Switch OCXO>Zenith. eliminated 2 boxes and power supplies. 

Setup WR902AC:
1. Look at the back of the unit. It should say the name of the device Wifi.
2. Power up the unit using the 5V micro USB. Give it a minute.
3. On a computer select the 2.4Ghz Wifi from the TPLink. Type in the password, this is on the back label on step #1.
4. Once you’re connected, go to http://tplinkwifi.net
(If this step does not work use a fresh browser after deleting the cache)
5. The first time it will force you to set a new admin password.
6. Once you’re in the menu, cancel the quick setup.
7. On the left bar go to the Wireless 5Ghz. Turn off this radio.
8. Go to USB settings. Under Storage Sharing and FTP Server tabs disable both.
9. Go to System Tools, Time Settings, and click on Daylight Savings, Save, Get time from PC, Save. Close the browser.
10. Unplug the power from the TPLink.
11. On the left side of the device move the physical toggle down to CLIENT.
12. Reattach the power. Select the TPLink wifi again and connect.
13. Open the browser again and go back to TPLinkwifi.net
14. Go to Quick Setup. Click Next. Now select CLIENT. Next.
15. There should be a list of your home’s 2.4Gz wifi channels. Select your Wifi with the highest signal strength. On the next screen it will ask for your Wifi password. Click Next, then Next.
16. At the end of the setup it will ask you to click FINISH. Then the device will reset. This will take 2 minutes.
17. At this point the TPLInk Wifi ID will disappear from your computer’s Wifi list. The TPLink is now an extension of your home Wifi. If you connect your computer to the TPLink via LAN it will be an ethernet hotspot (turn off your computer’s Wifi first!). Run a test by opening a browser and you should have normal internet access.
18. You’re all set up! Connect the TPLink to your music server using a dedicated low-noise battery and enjoy! Make sure the battery back is detached from any charging input as that can add noise.