Cable replacement solution for Bose Triport (AE1)

The 3.5mm mini-jack of my Bose Triport (AE1) was about to fail, and I couldn't throw away those headphones "just because of a cable". I also wanted the repair to look "factory".
After a deep-dive with Google, I learned that some in-ear heaphones have detatchable cables, with neat connectors (MMCX). Enter Aliexpress, where both cables and connectors are sold. Furthermore, some cables offer microphone and controls. Neat upgrade!

I bought the following parts:
2× https://www.aliexpress.com/item/4001265010893.html type C
1× https://www.aliexpress.com/item/4000087427502.html

I re-used the original cables to connect the drivers to the connector.

The mechanical fit of the connectors is OK even without 3D printed part, but there was a gap around them and the cables would touch my earlobes. I therefore re-soldered the wires at an angle to the connector, and covered the connectors with heat-shrink tubing.

I therefore decided to improve the situation, with this tiny part that fits b