I’ve found the bug, the split mode should work now. Additionally I’ve added a secret option to revert the forward/backward handling. You have to set a forward/backward direction first with H for the option to show up in the Advanced Preferences or you have to create it there as a simple preference.
The preference kindahackedinutils.oppositeSimpleDirection then has to be set to true. This will work in combination with the natural direction preference. Only when natural direction is disabled the forward/backward areas will be switched if the hidden preference is set to true. So when you point in the direction of the way behind the sign it will get backward instead of forward.