Back in 2017 my friend Frank and I took a rather comprehensive 28-day trip. Texas Eagle Austin to Chicago, hotel overnight, California Zephyr Chicago to Sacramento, hotel overnight, California State Railroad Museum, then Amtrak California to Oakland, several days there at Jack London Square, then Coast Starlight to Seattle, several days there, then Empire Builder back to Chicago, hotel overnight, Capitol Limited to DC, NE Regional to Baltimore, hotel overnight, B&O Railway Museum, NE Regional again to Philadelphia, hotel overnight, Battleship New Jersey, NE Regional still again to NY Penn, a few days there, Empire Service to Albany/Rensselaer, hotel overnight, back the next day to NY Penn, NE Regional to Boston, taxi to N Station, Downeaster to Portland ME, hotel two nights, laundry, sightseeing. Then Downeaster (Upwester?) back to Boston, taxi to S Station, Lake Shore Limited to Chicago, hotel overnight, Texas Eagle back to Austin. Whew!
In Seattle, we tried to check our second bags through to Washington DC, but the guy there wouldn't do it because of our overnight hotel stop. Said we had to be on the same train as our bags. So, we kept them with us, wrestled them back to and from the hotel, and made it work. Still.
In Boston, we decided to try to check our bags to Austin, so we found the baggage room and asked, and a good ole railroad guy said, "Sure, why not?", got the AUS tags, and we just had our backpacks for the two days.
Got to Austin, they didn't come off the train, but the stationmaster saw our interest, and asked if we were the Boston to Austin bag people, and went and got them for us. They came down the day before.
Policy seemed to be made up on the spot, up to the person on the scene.