Streamer upgrade advice.

A quick look at the CXN specs and I did not see native support for Apple Music. You also mention Airplay, iPhone and Mac. Can you describe how you are  currently playing music and how you are connected to the CXN?

Rose250a everSolo A8 support AM natively that sound reasonably good and are in your budget

Airplay, Apple Music snd ALAC isn’t exactly an optimized streaming setup. You can improve it by getting a streamer with native apple music support but it’s still not going to sound as good as qobuz or tidal. 
Just as an experiment can you do a free trial of either qobuz or tidal with your CXN and compare it to AirPlay/Apple Music?  Stream these natively thru the streamer app. Start there and see if you can hear any differences playing the same tracks. 

@zlone, CXN and Mac are on the same wired network. Airplay from mac to cxn, controlled via apple remote. Obviously this has limitations. 

I'd stay where you are at until you decide to upgrade your streaming services. 

You can get a better system by converting your music files to the general flac format and storing them on a NAS.  Then get a Bluesound node nano and connect the usb output of the Bluesound node to your dac.  Run an ethernet cable from the NAS to the node nano if possible, otherwise you can use wifi.

I think the Node may need an ethernet cable connection to a wi-fi extender at least.

Sadly, it's time to move on from Apple.  The most cost effective solution would be to get a streamer/server with some onboard storage.  Relocate the music you own onto the new device then switch streaming services to Qobuz or Tidal.  This should really unlock the potential in your system.  

If you stay with Apple you will always be handcuffed. 

@rick_n choice for a good streamer/server with on board storage? 

Here’s a very good streamer w/ internal storage at a good price that also has an excellent app that’s very user friendly.  Very good customer support as well.  If interested move fast because at this price it won’t last long.

https://www.usaudiomart.com/details/650237304-innuos-zen-mk-3-server/

My eversolo a 8 is a bargain. Some say customer service is lacking. 

You have to be a mug to pay thousands of dollars for an audiophile streamer with built in storage.  You can get a good NAS with RAID protection for less than $500.  When a hard disk fails you just swap it out for a new one, instead of paying thousands for a new audiophile streamer box.  Save your money for the DAC and amplifier. 

Here's a  review of the control app for Synology NAS devices. https://www.youtube.com/watch?v=uZQE1xp76QY

It controls any DLNA or UPNP streamer on your wifi network.

And a cheap Bluesound or wiim streamer can produce great sound with a great dac, amplifier, and headphones/speakers

Innuos!

Point 1&2 just killed you. Get off of computers and Mac in particular (if you're serious).

Also, forget any improvements unless you're willing to shell out $5K or better. 

This is all assuming the rest of your gear is above par. 

Have a look at the streamers and streamer/DAC from Lindemann of Germany. You can also add a USB drive to the back of these devices and play locally stored music files. Also, the Volumio devices from Italy are very well respected. Both brands make a streamer without DAC or streamer with DAC.

I was stubbornly attached to Apple Music airplay etc etc. I gave up when I tried qubuz with roon. It works the way it should…. Now my digital stream is sublime. 
 

sadly, Apple just isn’t serving hifi very well at all, despite their lossless catalogue. 
 

r

Like others have said, moving on from Apple to Qobuz or Tidal will open up more hardware options for consideration, and you may find the quality from either of those two superior to AM.
If you are sticking with Apple, consider an Eversolo DMP-A8 ($1,980). Plays AM natively so you get the full high-res playback, and it has onboard storage, up to 4TB (additional cost), to store your purchased music. 
I have the original A6 and plan to upgrade the power supply to LPS. I feed that via USB into a Denafrips Ares 12th. I have 2TB of onboard storage and connect a CD player to the second USB port for playback and ripping to the HD. 
There are lots of features and functionality, even when "only" using it as a transport. Add to your audition list.

I, too, am. Dedicated Mac user, since January1985 while stationed with the Army in Europe.  However, I recently added TIDAL to my system, still through an iPad Pro.  A comparison of the same songs between the two services was simply stunning, with far better imaging nd somewhat better tonal qualities immediately evident.  So, I have an Innuous Stream 1 with added reclocker on order.  Given the quality of your system, I believe the addition of a better streamer will make a significant difference but also that switching to TIDAL—its monthly fee is modest—will also make a huge difference.  Once you get your new streamer, check out Tidal and Qobuz via their free trials.  I was “sold” in less than an hour.  Wishing you great music!