Just a quick report back.
The trip to Germany from ZRH using the ferry went beautifully. We’re glad MrLapLap had the chance to travel via Romanshorn to Friedrichshafen in the Switzerland to Germany direction but would not feel so confident with the return on this route.
Today’s weather has been glorious and there was plenty to do at Lindau-Reutin (as well as the food van and bakery there is a multi-storey shopping centre with sweeping views of the mountains from the top)

Lindau-Reutin Station
He’s now on the train to Zurich Airport.
The Trip.com live tracker has been excellent.
DATA POINT - the system says sit in “any available” 2nd class seat but not the case, he and a lot of other people were made to vacate them, they were reserved. He said the train is crammed with people with luggage, suitcases everywhere (he has the one, work tools). Turns out there are reserved and non-reserved seats with the majority being reserved.