Which HDMI audio extractor works best with the Helix TV terminal?

Every Illico HD terminal from Videotron that I have ever owned in the last 17 years has had an optical audio output (TOSLINK). Unfortunately, the new Helix TV terminal has no such option; it only outputs the audio over its HDMI cable. My 15 year old AV receiver has no HDMI inputs, so it can't extract nor decode the digital audio from the Helix terminal. I would need to purchase an HDMI audio extractor. There are many extractors on the market designed to interconnect Blue-ray players, laptops, computer monitors, TV sets, PlayStations, PC’s, streaming devices, etc. There are reports that suggest that Helix like devices will provide the digital audio only in stereo if the target display device (TV) is a stereo device.  There is also the suggestion that when a Helix like device plays back a recording saved to the "cloud", the original DD5.1 is replaced with stereo. In my mind, the perfect HDMI audio extractor would pass 4K and 2K video at all frame rates, extract the surround sound audio that the Helix terminal generates regardless of the digital format (DD5.1, DTS, etc), and be compatible with older and newer AV receivers having optical inputs for digital sound.  Another workaround would be to connect my TV's digital optical audio out to my AV receivers digital optical audio input, but my TV may not "pass-through" the digital audio from the Helix, as my TV does not support ARC or eARC. Is anyone successfully using an HDMI audio extractor with their Helix terminal and older AV receiver? Thanks for any comments.