I've booked (through Eurostar, as a single ticket) a train trip from Amsterdam to London with a transfer in Brussels. The first leg is on Thalys, the second on Eurostar. The ticket leaves about 45 minutes to transfer in Brussels.
The email I got after booking says to arrive at the station 90-120 minutes early(!), I guess for passport control. But I've taken Thalys to Paris a number of times, obviously without passport control, and without any extra time at the station compared to any other train.
What checkin procedure should I expect here? Do I need to do anything special in Amsterdam before boarding the Thalys? Or am I safe arriving 15 minutes early in Amsterdam, but will need to hope I make it through checks in 45 minutes at Brussels?