>>106529111
Apparently those pigtails are used in drones, so drone hobby stores might have them. Seems they're occasionally used in IEM cables too.
Although I did find this:
https://rfbat.com/products/1pair-blue-shell-mmcx-connector-right-angle-for-shure-se215-se315-ue900-earphone
https://www.ebay.com/itm/157080719715