There is a way to have turbo and supercharger together in same engine by using additional modification slot for turbocharger and intake slot for supercharger, I don't know any better way of achieving that. Problem is that I can see only supercharger in forced induction debug and also boost gauge will show only supercharger boost, not total combined boost. In video it is possible to see how turbo wakes up after small moment, when you look at engine torque at engine debug, torque curve app does show total effect of dual charging, but I would like to see turbo boost pressure or/and turbo rpm somehow. Not sure if I need to implement dual charging in different manner or if some UI magic would be needed or if this is something developers would need to look into, I guess first one is most likely though? Update: My current files of this that are complete mess at the moment
The UI (apart from the torque relates things) does not support this at all right now. I'm afraid apart from manually inserting prints in the turbo code there is no way to display that data at the moment.