And it would be very helpful to manage publication of complex changes in this area via the launches feature. However the launches UI does not seem to support this, is this something that we could customise and it should "just work" or am I missing something here?
I don't think it will work even if you enable the feature from UI after customization. The backend implementation logic of Launches use PageManager and MSM APIs so I don't think it will work on product data.