So, can EasyDABv2 be used to send GnuRadio quadrature signals to the air? For sure Yes, it can!
With simply modified firmware, with removed DAB-blocks, this hardware is turning into the EasyQDUC (Easy Quadrature Digital Up Converter). And it can be used to send any signal with 192KHz quadratude samplerate or lower. For example, it can be used as DRM or DRM+ transmitter, FM-radio station or any other signal transmitter that fits into ~182 KHz bandwidth.