As expected, the ferries should be absolutely fine... We had no hassle taking a bullitt on board last year (Brittany Ferries).
I have no experience of trying to get a cargo bike on a train but trains and bikes in general are a pain in my experience of trying to take a touring bike on board. But there's always a way! For me it was using (slow) regional trains rather than high speed alternatives unless you're willing and able to dis-assemble and wrap/disguise the bike. I would guess that the smaller the cargo bike, the easier a time you will have but every train operation will have their own size limitations.
Not sure how that helpful all that is but I guess the tldr is that the internet is correct, do it!
Thinking about getting an Omnium for touring with a small dog 🐕. Wondering if anyone on here has done that and knows if the size of any or all of the cargo, mini-max or mini are problematic for ferries and trains? Guessing doable on a ferry but all but the mini will be a nightmare on trains in UK and Europe?
The dog (only 6kg) is my girlfriend's and she's had him in a basket in a front rack and in a backpack for short rides but hoping the design of an Omnium would offer a more stable platform so we can do some distance. Anyone tried it? Internet reports say do it, but if anyone's got experience would be great to hear.