Remember that Eurostar demands an hour for pre-boarding security, Immigration, and customs at the BOARDING station between England and the Continent. They will not guarantee Eurostar boarding if you do not make THEIR deadline. It doesn't matter what someone here tells you, so read the Eurostar rules. Brexit has not made this any easier.
Thanks, I've taken Eurostar in the past and I'm well aware of the rules.
It's too bad you might be exposed to Walkup fare levels on Eurostar. Be sure to check times of day when Business travelers might be less likely to take Eurostar, in the hope of saving some money - unless total travel time is of the essence. You don't seem to have factored in travel time between ferry terminals and major cities.
I'll decide in the next couple of days so I can get an advanced fare. My ferry plans include travel to the ferry ports. I just haven't posted them because they weren't relevant to my questions.
I'm not a novice traveler.