Apple TV Streaming Sound Quality vs Streamer?

Steve from Empirical:

Does the Synchro-Mesh improve the optical out of most TVs, especially Sony?

Does the Synchro-Mesh improve the optical out of the Apple AirPort Express (sadly becoming legacy)?

Do you know of a high quality AirPlay streamer (source only) that can take the place of, or improve upon, the AirPort Express?

I use an Apple TV with an optical out into my DAC.  I also have several Airport Express devices (with optical out) that I can use.   I cannot tell the difference between the bit-perfect Airport Express (16/44.1) and the upsampled Apple TV (16/48).  In my casual testing, the sound quality of either apple device equals the sound quality of the CD I ripped the files from.  As long as I'm not concerned about high res (higher than redbook) or "fully unfolded" MQA I am completely satisfied with the sound quality.

I guess I don't have the gilded ears (or revealing enough system) to hear jitter.  As much as I have obsessed over this, I have come to the conclusion if I cannot hear it (including long listening sessions), I won't worry about it.  My observations match other observers who have written about this on the internet.  I'm sure that somewhere along the line, it makes a difference.  That said, I do think I notice a difference between USB and SPDF (at least with my equipment).  After much listening I prefer the SPDF connections over USB.  Before I invest in a Remedy reclocker or USB "Decrapifier", I think it's more likely I'll move to a Micro Rendu (or something similar), or an asynchronous USB input DAC (lots of upgrade options here, and more hitting the market every day).

Note that the newer Apple TV and AEX units do not have SPDF out.  Plenty of older models of both available on the used market for around $50 or less.

As an adjunct to what I wrote previously, I must admit that I do enjoy Tidal MQA when running directly from a Mac mini>DAC (no AEX or Apple TV).  It's my opinion that most of the difference is in the mastering.  When I switch over to the AEX (limited to 16/44.1) and play the same Tidal files, I think it sounds the same.  When I compare the same Tidal tracks to an older CD (different mastering), I notice a difference.

I have the same experience when I listen to hi-res files (direct to the DAC from the Mac Mini) vs. the same files streamed through the AEX or Apple TV (downsampled to 16/44.1).  I just thank my lucky stars that either my ears aren't good enough or that my system is not revealing enough to merit worrying about anything higher than 16/44.1!

Apple device > DAC (I have several, my current favorite is Schiit's Bifrost multibit) > Odyssey Candela pre-amp > Odyssey Khartego power amp > Harbeth P3esr speakers.  Also have desktop system with Audioengine DAC and A2 speakers, and a headphone system consisting of AEX > Schiit Modi Multibit DAC > Schiit Vali amp > Senn 650 or Grado SR325e.  I probably notice the difference between file types most with headphones (no pesky room acoustics to deal with).

Full disclosure:  when I really want to raise the hairs on my neck, I play records (another discussion)!