Playing at 7680x4320, recorded with shadowplay at 3840x2160 which seems to be the highest resolution possible to record at currently, not the best quality.
Tools used: Custom DSR Tool, D2MultiRes. More info below.

If you try to jump too far out and not diagonal, you just jump up at the same spot (through the floor sometimes), which is why i kept the jumps decently short in this video.
Super low framerate & delayed mouse movement.

Managed to run the game in 10240x5760 (10K) as well, but you just see more unrendered space, not very exciting.