Cargo Bicycle I Want To Know What Is Descent Speed To Be Safe With My New Groozer Cargo Trailer .?

I want to know what is descent speed to be safe with my new Groozer cargo trailer .? - cargo bicycle

I'm an experienced pilot with 3 seats Bike Trek 520, Raleigh, C 500, with amendments), mountain biking (hard history, and I made a small trailer behind a bicycle than 4 months of Cascade Highway. Do not overload the trailer with a payload of 35 kg. I prefer baskets but sometimes have no other choice if I bring my camera equipment.