Yeesus, not again.
You’ll notice that nowhere in @danny’s erudite posts does he speak of the sonic benefits of MQA. I suspect he doesn’t want to be drawn into that sh*t storm.
For those people who want to canonize Stuart for his invention, there has never been any concern about bandwidth or provenance. They believe MQA provides an improved SQ.
Wasn’t that your real question?
If this stuff is a hobby to you, then I suggest you play with all the settings as it’ll give you “more hobby” to play with.
If this stuff is a bore and chore, then I suggest you leave it and enjoy the music.
If you have Qobuz, your MQA settings will rarely matter, as the vast majority of content on Qobuz is not encoded with MQA. There is some, but it’s only from sources that only released MQA-encoded content.
Way off topic, but literally, right now, I tried to play a track that my kid was playing in Spotify.
JVLA / Such a Whore (Instrumental)
Roon found it on TIDAL but not Qobuz. I decided to check both services at their own sites, TIDAL has it, Qobuz does not.
Now I have to go explain to an 8-year-old what “Such a Whore” means. Wish me luck, and you all have a good weekend 
[Say] The “original” file was some high resolution file, maybe 384khz even. MQA “folds” this to a CD resolution which saves both storage space and bandwidth (beneficial to the streaming provider). There is an unfolding that happens at playback which allows you to get back to the original resolution of the file. Software can accomplish the first unfold only, as others have pointed out, and you’re seeing the result of that first unforld. This does not get you back to the original resolution but gets you “high resolution” or beyond CD quality.
There is stuff in the MQA encoding which tells the MQA software how to unfold, and that exists down in the “audible” (audible but below the noise floor) range of the “CD quality” file. During unfold this MQA stuff is moved into the resolution beyond human hearing after first unfold waiting for the next unfold to find it and act on it (which occurs in hardware usually a MQA DAC). My opinion is that this is a good thing so I leave Roon MQA Decoding on.
There are filters and other “things” applied to MQA encoded files but that gets into the sound quality (pro or con) side of the discussion and I think you just wanted a reason / opinion on why to let Roon do the first unfold. Well, again, my opinion is if its MQA at least expand the resolution where the “MQA stuff” gets moved up into an area where I’m not able to hear it. This doesn’t “remove” MQA, there was a great article awhile back done by GoldenSound about this, but I think it’s closer to the original vs. leaving it alone.
If you want to get away from MQA completely don’t use Tidal. If Tidal is going to force MQA on us then you’re darn skippy sure I’ll utilize the feature in Roon that gives me a slightly better chance of enjoying the format.
As far as I know, MQA starts with 44.1, 88.2, 176.4, 352.8 (maybe higher) and compresses to 44.1. Or, it starts with 48, 96, 192, 384 (maybe higher) and compresses to 48. Then, MQA files are transmitted as 44.1 or 48.
Tidal and Roon (and maybe others) can software decompress (first unfold) from 44.1 to 88.2 and 48 to 96. This is the “decoding” process. If you have an MQA rendering DAC, it can further decompress (second unfold, etc.) to the original resolution or up to the DAC limits, if lower.
A fully MQA capable DAC can do both MQA decoding and rendering, but if you’re using Roon DSP, this will be lost unless you let Roon do the decoding step.
I used to think MQA sounded better, but I have changed my mind. On the other hand, I don’t think it sounds worse and I have no philosophical issues with MQA. I like to use MQA when using cellular internet.
There’s no objective advantage to MQA. It’s a different mastering and if you have MQA capable equipment it’s played back with reconstruction filters designed by MQA that are slightly different sounding from others.
Whether that sounds better or not, or different at all - is individual and subjective, and also possibly setup dependent.
In your case, without an MQA DAC, Roon is simply unfolding the compressed MQA file - there’s absolutely no magic going on there. MQA files are mostly encoded at 88 or 96k and Roon is simply decompressing the file. There’s nothing else special or proprietary going on.
On your system it is then played back just like any other file with your regular reconstruction filtering.
You are right - that streaming bottleneck is sort of 2010.
Qobuz, Amazon, etc are streaming hi-res without MQA and there isn’t any issue.
5G adoption is happening right now, and data plans are getting cheaper by the month.
People want to stream 4K movies on their mobiles. And that’s what they’ll get. Demand will drive this.
Compared to streaming 4K content, music streaming on-the-move, even in 24/192 is undemanding for the networks. Compressed MQA files are now irrelevant IMO, and MQA cannot demonstrate a competitive advantage. Why bother with MQA? The streaming companies like Tidal love it because it’s cheaper to stream and reduces their overheads.
Yes. For some MQA recordings this restores the musical content from 22kHz to 44/48kHz if you get a 24-bit stream with a HiFi Plus account.
MQA Core decoding / first unfold: yes.
MQA Rendering: no. This specifically requires a MQA product with analog output i.e. MQA DAC or MQA CD player, as required by MQA Ltd.
Disclosure: I worked on MQA integrations.
Except that Tidal - a very minor player in the streaming market (yes, barely a blip on the screen in the overall market) - is the only significant customer for MQA. And even at Tidal it’s just a subset of their paying customer base. Amazon (hi-res), Apple, Spotify, Google, and Tenecent haven’t adopted it and since it’s been widely available for 8 years, it’s pretty clear they won’t.
It’s already a failed technology. The company loses money every year, and is being kept afloat by injections of cash from one investor. As soon as that investor tires of wasting money on it, it will be gone.
I agree completely. MQA is now irrelevant IMO.
Thank you all for your input. I’m slightly more confused and knowledgeable at the same time 
No need for further replies. Thanks!