I guess I have 3rd gen eloftys (Eovan, supposedly the supplier for Boundmotor) and after ~300km this year the rear axle is bent by ~2-3deg upwards.
Most of the rides were on perfectly smooth asphalt, but those ~25km on cobblestone/other rougher terrain bent the axles in no time. I suppose they are not properly hardened/cheap metal.
tl;dr: if you don’t have perfect road conditions everywhere, stay away from DDs.