I measured the resistance between the sleeve and ring 2 on my Bose QC25 headphones: 5.6 kΩ
This led me to adding a 5.5 kΩ resistor to my plug, and it works:
Rings 3 and 4 are intentionally left unconnected. I don’t need headphone output.
With another headset that I tried, the phone, a Xiaomi 4X, did not detect it properly. That headset did work on ...