Rail Reverser block.

[Ithirahad]

Basically, a block that would compact a five-block system (NOT-gate with two activators adjacent to opposite-facing rails) for switching rails to the opposite direction, to a single block. On a high signal, it would switch linked rails/rotators to the opposite direction. On a low signal, it would switch them back.

 

[NeonSturm]

Button slaving rails.