Though this Mate is only rated IP53, the SIM card tray is equipped with a rubber gasket—something we usually see on "waterproof" smartphones these days.
To our surprise, we get the glued-down back cover off lickety-split—no heat required! A suction handle and a halberd spudger separates everything nicely.
A generously proportioned fingerprint flex cable keeps the back cover tethered for now, but it's such a long leash that we don't mind. On to the next layer.