Here is a quick mock-up of what I mean.
In image 1, the shorter chain-dog pushes the train up the lift. In image 2, when the chain trough indents inwards, the shorter chain-dog is too short to keep contact with the train and so train freefalls backwards. In image 3, after train is slowed by magnetic fins, a taller chain-dog further down the chain in position engages the train and pushes the train back up. In image 4, as the chain-dog is taller, it remains contact even when in the indented section, continuing to push the train up and over.
Obviously this is all speculation and is all based on how Gerstlauer make lift hills normally with the presence of chain-dogs located on the chain themselves to 'push' trains up. This may be a completely new design for Karnan but this is simply my thoughts.