we have some SFP's connected to our switches (these switches are supported by LMS) but they don't appear in the reports.
I don't see anything about these devices in the supported devices tables.
Is it possible to get them shown in the LMS reports (User Tracking reports, I suppose)? Are they supported?
No. Neither application delves that far into element management. The serial numbers would have to be tracked externally. You could also raise a product enhancement request with your account team to get this functionality in RME.
Getting the serial number for most GBIC and SFP interfaces is not possible in RME as RME will only get the serial number for containers.