STREAM_OPTIONS_CHARACTERISTIC
Stream options (read/write, one byte, firmware 3.8.1+): a bit per option, bit 0 DIGITAL_INPUT (every packet of the next stream then ends with a digital-input block, see PacketCodec.decode). A host writes it after subscribing to the stream packets and right before STREAM_START; the device applies it to that start only and clears it at every start (even a failed one), at a subscribe to the packets and at a disconnect.