Digital improvements possible?

The Stockholm 2 does 24/192kHz just fine, so with the right app you should be able to decode MQA in the Mac and play it back, as well as most offerings from hi rez stores (except DSD).

What you don't mention are speakers or headphones.

You should experiment wiht your MacBook on AC and on Battery power. If you find this makes a difference, consider buying a linear supply for your listening. This very much depends on a lot of factors, like where you plug the AC in on your DAC and Mac as well as how well your DAC isolates digital noise. So you may hear zero difference.

Unless your DAC stinks, there is 0 reason to go above 24Bit 44.1kHz (MQA and DSD are just marketing gimmicks), even regular CD quality (16Bit 44.1kHz) is good enough for 99% of use cases. 
  
Room treatment is something hugely important that is often overlooked.

Thanks for feedback so far, guys!
Erik- I have Vandy 2ceSig 2s and have tried to discern a difference between battery and AC from the wall with my Mac. I have a dedicated power line and Porter Port outlets and can’t tell a difference. Thanks for info on the Stockholm too!

MZ- I’ve wondered about that. There seems to be a lot of hype about hi-Rez, but I’ve not compared it with regular CD quality personally. I do believe Tidal is just as good as CD downloads I’ve done in iTunes. I’ve A/B’d tracks head to head and could tell no difference. I can seem to discern better quality on MQA albums on Tidal versus the same non-master album on Tidal, however. And I have some room treatments for first reflecting points on side walls and behind the speakers. 

I know now some people run JRiver, Roon, etc... is there an advantage sonically?
Since I stream Tidal via WiFi it seems to really slow things down for me. Do I need to upgrade my internet speed?
Any other tips are most welcome. 
Thanks again. 

Tidal doesn't really take that much bandwidth in modern terms, but if you are relying on Wifi, and are in a congested area (apartment bldg) that is more likely to be a problem.

Improving the front end of my system has been on my radar too. I run a reasonably quiet gaming pc > Live Dirac>sotm tx-usbexp>W4S RUR>DAC-2>LM508IA>Tekton DI's

A filtered outlet and usb card cleaned things up well. Live Dirac has always been the game changer in my system. The focus, imaging and detail is amazing, with amps retaining their unique characteristics.
You've got to choose between Live Dirac and MQA as the RC digital filter puts the kibosh on the MQA decoding. 

I was able to run a free trial. Be prepared to spend the money as you may not want to be without it once you've drank the "kool-aid"

Did I miss it, or did the OP mention his amplification?  There is a lot more to sound than just mentioning the source.

@lincnabby  
 
MQA is lossy, it competes with MP3, impossible to be better than CD or higher.  People who boast about 96kHz or 192kHz have no clue what it even means. Firstly, we can’t hear that high. Secondly, most systems can’t even reproduce audio that high (wether it be the DAC, pre-amp, amp, and/or speakers).

Are you using the USB or the optical output of the MacBook? I use the optical output of an iMac for a substantial part of my listening, going wirelessly to a Gen 3 Apple TV and Simaudio 300D DAC in my main system and directly to a Simaudio 100D DAC in my office. Of all the changes I've made in wires, tubes, etc., by far the greatest improvement to the sound in both systems came from putting a Wyred4Sound Remedy reclocker ahead of each DAC. In particular, the improvement in the office system was much greater than any amp or speaker switch I'd made.

I got the reclockers because of numerous references I'd seen to the high jitter from the Apple devices. And my experience bears out the importance of that. The change was considerably more dramatic in the office system using the Simaudio 100D than in the main system with the Simaudio 300D. I'm assuming that's because the more expensive 300D does a better job of handling the jitter on its own.

No experience using USB so my experience may not apply in your situation.

Thanks for all the input folks!
Erik- someday I hope to run a good quality Ethernet line directly to my MacBook, though our modem is on first floor and my listening room is upstairs. Still, perhaps it would improve SQ over WiFi. 

Brotw- thanks for sharing your experience with Live Dirac- I’ll check it out. I tried Audirvana for Tidal and was unimpressed, but perhaps it was a processing issue with my Mac. At the time I hadn’t upgraded memory on my laptop. Now I have more. 

Mahler123- I have an Osyssey Kismet stereo amp and a JE Labs 6sn7/76 tube based linestage. I think it pairs pretty well with the Vandys.