Did you manage?
The JDY-08 has the black rectangle piece, not to be confused with the JDY-10.
JDY-10 is the one one I managed to get uart commands working on, however I could not send any data even when connected.
JDY-08 responds +ERR to every command I send it. I read the firmware may be broke.
One thing's for sure, the Chinese are great at copying, and shite at getting things right.
I'll probably give up at spend $5/p on a Microchip or similar module.