I'm not sure if all MQA albums are tagged correctly or not. I'm also not sure about the 'M' bit. In the Auralic app (on my iPad) MQA have a MQA tag in a blue rectangle with each album
I was merely clarifying that even though you don't have an MAQ DAC then don't assume that you're not listening to MQA, as Auralic has a kind of MQA unfold in their app. I use an Aries G1 in to an Accuphase DAC50. When playing an MQA album the sampling rate changes to 96kHz (this is visible in display). The DAC50 is not an MQA DAC.
On your wider point; I've found taking time to optimise my streaming/network playing front end has led to very noticeable improvements to SQ (using same DAC), especially so viz a viz Tidal. It's now much closer to locally stored files (UPNP to my Naim Uniti Core). Local files still just about have the edge, but it's now at a point where the differences are marginal and not really relevant. Comparisons were made on local copies where mix and mastering were the same as the Tidal version, so far as I can tell. But Tidal don't tell you which version they're using so impossible to be absolutely sure. Tidal tends to use the most recent remix, etc., version
Also, if you weren't already aware, the streaming card in the Aries is the G2, rather than the G1 in the Altair. The G2 has more flexibility and performance and is demonstrably a 'better' streaming 'card' to the G1.
Given the care you took over amp choice, I would strongly recommend looking at your source. I was frankly amazed about how much difference it made in my system (my speakers are very revealing, but not bright and are capable of producing astonishing results).