Connect your Bluetooth as normal, once you have done this ONLY connect the rx of the OSD to the TX cable of your bluetooth-port (creating a y cable)
I did that without success on Revo board connecting to FlexiIO port.
But Bluetooth alone works very well with option PPM+Telemetry.
MWOSD works at the same port with PPM+MSP.
So it looks like they can't work simultaneously because of the protocol difference. Any solution?