Currently, if you clicked on a transition tile, you'll go to the next zone. It is only possible to stay on these tiles without transition if you don't have enough action points (on harder difficulties) or there's an "invisible" tile next to it.
There's a way to step on certain tiles that can't be clicked (when they are behind objects such as force fields) when "Alt" is pressed (not very obvious and not present in key bindings). Maybe if you press "Alt" or some other key (reverse highlight), transition shouldn't occur.
