SMB V1 and 2 are outdated and open for security hazards. So the preferred is V3. Not part of documentation as all Version works, But Volumio needs to know what version, when not using V3, hence the option field.
I’ve been active supporting JRiver for many years, but keep in mind that JRiver has a long history in comparison to Volumio.
Volumio is still young and it’s focus on bit perfect playback from multiple source, where JRiver drops the ball. As the almighty Jim, still thinks Streaming is not the future.
For every software packages, there are pro’s and con’s, so is it with Volumio.