Carrying kids on a bike safely doesn’t have to mean enclosing them in a trailer. Some child trailers are built like rally cars, creating a safety cage around your child. But a bike towing a trailer is also much longer than a normal bike, which means that you and your child are more exposed when crossing streets, turning in an intersection, etc.
Why not keep your child closer to you, on a long-wheelbase bicycle that’s built to carry heavy loads to begin with?
Standard childseats can be attached to the Mundo platform. The Bobike maxi, maxi+, junior work, the Hamax line too. The childseat attaches on the seat-tube like on any regular bike. Note that it’s necessary to help the plastic spread a bit around the carrier. No longer blot required. If you already have a childseat great, if not I would recommend to select the bike once you have the seat.