Oh! One small point still!

There is yet a small difference between the 4K and the International / Italian version. After the scene where Tuco and Blondie share the bounty for the first time (and talk about cutting Blondie's percentage), there is a cut to the next shot of Tuco with a rope on his neck.

This cut has a "spin" in the International and the Italian version; in the 4K, that's just a straight cut without any effects. Don't know how to describe this more exactly... the picture is kinda rotating during the scene change.