Those are the refunding parameters.

I have been sucessful in missing Acela Express First and having to take the slow train in business.

I said I missed the XYZtime Acela, can I get on the XYZtime in Business. The person at the station (lounge agent in BOS ClubAcela) essentially cancelled and refunded my Acela Express First potion of my roundtrip and I then purchased a Business class fare slow train for that cancelled portion of my round-trip.

So this was not a schedule or weather thing, but I did miss my train (so my ticket was cancelled in full (accommodation section too) within one hour) You could do it that way, but it is risky, of course. Nevertheless the agent let me stay in the lounge even though I was not really supposed to because I was departing on slow train Business, but that Boston ClubAcela lounge always has lees then 10 people in it anyways.

Good Luck!