The zebras level: 107+ .. 108+ with no picture profile or Picture Profile 2 default gamma; 95+ for picture profiles using HLG2 gamma; and 100+ for HLG/HLG3
And please, please, forget 18% metering. It's not metering, it's exposure that results in 18% lightness after standard development was applied. Metering calibration is usually for 9% .. 13%, sometimes as low as 6%, for extended low ISO it can be 18% .. 22%
The zebras level: 107+ .. 108