I am interested in this too. I think the BY-A6 is the only device capable of clearing DTC codes. It has many other advanced features as well for an affordable device.
Or possibly the TRACKPRO OBD620, but it might use NMEA 0183.
Looks like the CalAmp LMU-3030 does clear DTC, compatible with Traccar. Lowest price is $99 ebay.
I realized I posted on wrong forum for device information.
Anyone knows Traccar supports BY-A6 protocol, I haven't seen anything in protocol list or if its with some other name.
Here is document for protocol https://drive.google.com/open?id=1X7MKMJ9scA1wqhZnDQjo2x6m0sm94MSf