I had 4 SONOS connect devices (S1 app only) doing exactly this. I recently (last month) replaced them all with BlueSound node nano devices. They do exactly what you require - point it at the SMB server and away they go.
Bonus is they do it over SMB2 allowing me to switch off SMB1 which I'd previously had to keep running for the SONOS devices.
The Samba project has secured significant funding (€688,800.00) from the German
Sovereign Tech Fund (STF) to advance the project. The investment was
successfully applied for by SerNet. Over the next 18 months, Samba developers
from SerNet will tackle 17 key development sub-projects aimed at enhancing
Samba’s security, scalability, and functionality.
This is an executive summary of research that my colleagues Ronnie Sahlberg and Jonathan Maple did, published as a whitepaper with all the numeric details here:
Samba doesn't use the passwords or users in /etc/passwd directly. You have to map any SMB users into /etc/passwd users in Sambas database. Without that mapping they don't exist for Samba.
I'm talking about what is published on the GNU and FSF sites. Whether they still actively do it is an interesting question and I welcome your feedback, but I'm not spreading false ideas, and my comment is "education" about various aspects of licensing.
No one in these days of cyber attacks should be shipping unknown third party dependencies. How could you fix unknown dependencies in case of severe CVE's in them ? Unknown third party dependencies are a sign of utter amateur incompetence in product development.
Once you have all third party dependencies cataloged, licence compliance should just shake out in the wash.