I use chunky, load 1000 chunks, not a single one shows when turning on DH again. No errors, crashes, or anything.
Solution
DH has shader support code in all version from 2.1 onwards This code changed a couple times so Oculus/Iris 1.7 to 1.8 supports DH 2.1 - 2.2 And Oculus 1.8/Iris 1.7.5 support DH 2.2 and onward