There is no obvious way to select sound card and sound system (jack, pulse, alsa, portaudio or similar). This should be added to the UI. Most more serious audio users I know working with jack have also a second soundcard. Jack/Pulse seems currently to be the only possibility to externally force to go to the second card (something I can live with but users who don't use jack/pulse certainly not). I often switch between sound systems and don't want to install two binaries of rezound just for that task. Also basic sample rate etc. options are not in the recording (or wherever) dialog.
So this selection would include
- Selection of sound system
- Selection of sound card
- Manual setting of sample rate card and similar options as required
- Automatically start sound system if not running