This is the case at least with the pick up items and chop trees signals. I was experimenting with adding a signal to control the nearest enemy distance to be considered safe and noticed that the pick up items job was not being executed at all. The interface also had a tree gathering job from my previous experiments on figuring out how it works. It's quite unexpected that multiple jobs in a single interface don't work, given that it has five signal slots (enough for all the different jobs plus the "nearest roboport only" control signal).
