Perhaps a discussion point, but it is my view that users do currently (in t1) use the possibility to immediately change a workflow to do implicit iteration on its input ports by providing more than one value, even if the first services in the list expects a single value. t2 does not support this and is stricter on that the input value needs to match the input port's depth (which again has to match to the depth of the next service, since there is no way in t1 to specify the depth on an input port directly). This could easily be achieved by wrapping the translated t1-workflow in a nested workflow. For core t2 workflows we probably want to keep the current strict rule.