If I condense the proposal down I get the impression that you want a checkbox to decide whether a chain signal allows a train through only if the tail can clear the next normal signal instead of getting the nose past the next normal signal. I know this is an old thread but this really seems the rig...

This is a map oddity a friend and I found while playing a vanilla multiplayer map together. It was rail world and we tweaked a few ore settings (settings + world attached), but nothing much. The world was first created in 1.17.32, though we are keeping up with all of the experimental updates so it h...