Intel Ark claims 32GB limit in the first place for Kaby Lake Refresh chips but Campuspoint tested 32GB sticks (64GB) with the T480 and it worked. Indeed, it see

Intel Ark claims 32GB limit in the first place for Kaby Lake Refresh chips but Campuspoint tested 32GB sticks (64GB) with the T480 and it worked. Indeed, it seems every Intel chip supporting DDR4 SO-DIMM supports 32GB sticks.