So I figured it out. You have to lay track diagonally, then you get a spacing of 3.

Such a fu#king puzzle game sometimes.

Even just a a double-sized chest (2x1) would solve this issue. But is there a better way currently? I hope I'm missing something, because this feels like a big oversight.

Trying to have a single train input to my main factory interact with a series of different input train lines. But I can't lay track so that stack inserters from one track input into chests that output into the other track via stack inserters as well b'c track can only be built one every other square ...