Hi David,
Plan for the full support of SSSD running as a non-root user is in scope of interest of the SSSD dev team.
I can't provide you a precise time frame for this but some preparation already started.
This transition is not trivial as by design SSSD was alway running as a root.
Keep in mind that on top of the code changes a lot of testing needs to be done to confirm that the final
result will be secure and perform well.
After fast check those are some of already existing upstream issues related to SSSD running without root:
Best regards,
Pawel