LumiNUS no longer issue and support guest accounts. If you have any concerns, please share with us the reasons here (NUSNET login required).
Any account creation/activation process will be handled by NUS IT. More details will be released soon.
When the integration is built, unlike the "Export to IMMS" in IVLE, there will no longer have "Export to IMMS" in LumiNUS. You can simply go to IMMS and do an import from LumiNUS.
Some of the staff and student photos are not available yet. Thus, you most likely will not be able to view the student photos in the Class & Groups.
Attendance view for students is not available yet. It should be ready by the start of AY19/20.