Digital audio to receiver from MacBook Pro

How best to get digital audio from my 2016 MacBook Pro to my receiver, using minimal $ and cable clutter? Ideally, this would be an adapter that attached to one of the 3 USB-C ports off the back of my 5K LG Thunderbolt 3 monitor, to maintain the clean one cable desk solution, but that USB-C to optical audio adapter doesn't seem to exist.

I attached the receiver via a USB-C to HDMI adapter, which works if I attach it to an extra USB-C port on the opposite side to where the monitor is attached (negative point 1). Although digital audio passes just fine, MacOS automatically creates an extra display for the HDMI connection, although none is attached, creating an extra space where windows can go to die (negative point 2).

In the interim I have settled for connecting the receiver via the headphone port for stereo sound (I apparently am one of the few that has used the optical function in previous MacBook Pro's headphone jacks).

Here are the best solutions I've yet devised. Will 2 or 3 work? Or is there a better solution or adapter I haven't yet found?

Solutions:

1. OWC Thunderbolt 3 dock ($300). Yes, sure this will work, easy as pie, but it's overkill, overpriced, and I was hoping to otherwise embrace USB-C and avoid more cable and desk clutter. Other new docks don't specify digital audio output.
2. Chromecast audio connected to optical input of the receiver ($35). I am not sure if this will appear as an overall audio output device from MacOS. If it would this seems perfect.
3. Old iPhone 4S (free) + iPhone HDMI adapter ($39) connected to the reciever, plus some old 30pin USB cable to charge it somehow. Install Airfoil on the old iPhone to make the iPhone & receiver appear as an Airplay target for audio.
4. Some magical lightweight Airplay bridge that attaches to receiver via optical or HDMI, which I haven't yet found.