Hey @RKP,
I am not able to discuss for future plans, but you can keep checking Trueplay-compatible devices and Sonos products for any changes in the “Coming Soon" and “Not Supported" field.
So I used an iPhone and I set up the speaker as an independent speaker not a stereo pair and quit tune would not run.
That shouldn’t be happening if your iPhone meets the requirements. Can you check on the back of your Era 300 if the microphone is switched upwards? You should see a green colour on the switch to confirm it is not muted.
If you are still not able to perform Quick tuning on your Sonos Era 300, I recommend contacting Sonos Support, as they have tools at their disposal to provide you with help and advice specific to your system and what it reports.
I hope this helps.