Would a binding with stiff baseplate and soft highback be forgiving on a jib board like the draft or artifact rocket? Or should I just look to a complete forgiving binding?
This depends a lot on preference. Some riders always want very supportive (less forgiving) bindings, even on pure jib boards. A moderately stiff base will restrict board flex a bit but the combo that you have mentioned above is still very common for park and play boards.