I NEVER ever call a US firm after hours, because you get routed to India, where they do not know WTF they are talking about. They look shit up on index cards.
Well, I called them today, got some guy with a British accent, so at least that's better than India, and he confirmed it. There's no way to trade simulated with Active Trader Pro. He said they used to have a demo-type thing through a third party app that didn't work well, so they discontinued it.