I was curious if it's possible to load a transport, stop its harvesting run (with ore inside) and then send it on a regular transit through the gate, wherein it can pick up a different harvest route and deposit the ore. I think this highlights just how difficult it is to manually control how ore moves from one place to another, but was just a thought. The text only says harvesting routes can't go through the gates, not harvesters (carrying ore) on a transit route.