I was able to install the system with the standard stretch (9.1.0) installer (DVD ISO on a USB stick)

The wired ethernet worked without adding any non-free firmware packages. For wifi I needed to add firmware-iwlwifi from non-free.

When installing grub to the EFI System Partition, the hack for installing to the removable media path was not necessary.

The ?T460s page mentions problems with the stretch kernel, HDMI, suspend and trackpoint. I'm running the stretch-backports kernel 4.11.6-1~bpo9+1 and these problems were not observed on my T470s, I've tested all hardware except the SD card reader and Smartcard reader and everything appears to be fine.

The Lenovo Thinkpad Thunderbolt 3 dock is troublesome: