This is the charging clip for the Jaybird X3. Might work on X4 as well.
I have attached images of the pogo pins and the micro USB connector board I used here.
I haven't tried it out yet, but should work. If there is any updates I will update the file accordingly here.
Please makes sure you get the pins correct otherwise it can damage your earphones.
Generic PLA PLA
Gray and Black
i printed quite slow, and it took 1 hour. used my profile for figurines.. turned out pretty well