I for one prefer the classic looks of the tripod-masts, though.
Just went through my library and looked at some photos of SMS Mackensens' stern during construction.
The markings do indeed go all the way down between the shafts. Quite interesting, never noticed that before.
I wonder if those are draft markings after all, because why'd you need them there of all places? (apart from when at dry-dock?)
The WWII BB's did not seem to sport something similar.