I also have 64GB on my work T480 (non-s) despite "max" being 32GB.

The Lenovo-reported max RAM specs often do not take into account newer larger memory modules released after the laptop (or at least I believe this is the reason for the discrepancy).

I have also put a NVMe in the WWAN-port, I found out that the Transcend MTE452T (TS512GMTE452T) has the right M.2-port (B+M), and it is a compatible NVMe-drive and not a SATA-drive which some of the disks of that form factor is.