Why not replace expensive mode with a customizable research science cost multiplier?

That way, players wanting a longer and slower playthrough, still get what they want, and it doesn’t mess with the recipes.

I tried running some smaller 3-way intersections on the test bench with several lengths of trains, but noticed that for certain lanes/directions, trains end up waiting a very long time before they could pass, sometimes until at the end of the test when all the traffic cleared up. Clearly, when train...