Hi light illusion. I'd like to just ask a question about your brightness pattern? Does it have a BTB square at all, and if it does is it by any chance the last square on the image?
The patterns are all full data range, so they include 'sub-black' and 'super-white', which are the correct terms to use.
But this depends on how you display the images.
You need to understand if the workflow / signal path you are using is re-mapping the image levels/data, or clipping.
Most home systems will re-map, so there will be no sub-black, or super white.