The reason for this discussion with its huge posts must be an emotional twist, because it makes no reasonable sense.

The persons who used Unity3D are longtime users of A6, and they know what about they speak when they compare the engines.

Kabus works with the dynamic shadow system of A6 only, because it uses extremely restrictions of view and rooms. There are always only very view entities with a dynamic shadow visible. It is one of the very very few games where the makers where able to make reasonable use of the shadow system.

For my more plattformer-like game with a free far view, and up to 30 NPCs it was useless, because everything got too slowly.