I'm not a huge fan of the 0.1" dupont headers as they are not super reliable (no retaining clip, no keying for idiot proofing...):

So, I made a PCB with IDC headers (10-pin header for the D-pad with clickable rotary encoder; 6-pin header for the Renault 3x3 matrix remote control).

Here is the link to the EasyEDA project (where you can download gerber files and BOM):

https://easyeda.com/moimeme4/mergeBT-4f19506c93c54159ba06ac12d7cdefa4