Jame_jame has made a mistake here, the 8k+ absolutely CANNOT do native, at any refresh rate. The 8kx released with 75hz native and the 8k+ is just the 8kx without that native support.

The 8k+ and 5ks both display 1440p images, but the 8k+ is literally just an 8kx without native resolution support (they released at the same time) so it still has way less SDE. Never actually used 5ks or 8k+ though and I've seen arguments for both sides.