I wonder if I am asking too much for a robot to clean. I know that cleaners in general have issues with steps/benches. And that fake-infinity-edge - I wonder if waterline can be cleaned there at all with any robotic cleaner? Any ideas, and especially experience, is greatly appreciated!
Robots in general do not clean benches or steps.. Not to say they don't get up there sometimes, but they are not designed to clean them.
I really doubt that they will clean your slanted water line tile... They are made to clean a vertical tile line.. Assuming they even tilted as much as your tile, I'm pretty sure the robot would see that as problem and reverse its movement.
Your best bet is to make a friend with someone that owns a Dolphin and borrow it for a day or so...