Did some exploring to find more patches - I even finally made a spidertron to make exploring lower effort.
Found some good copper patches though (looking to have at least 10 good copper mines active), so it was worth it. Just need to get them on rails.
Also considering making depots for my ore trains, so they can fill up and then wait nearer the smelting. I have a 4-stacker for each smelting column though, and since each smelting column only goes through a little over one train a minute, I think it should be fine. Maybe if I needed to go further out, but with the size of rail world patches I don't think I'll need to stray too much further.