In terms of the idea, it is meant to be done as US based thing - tapping into networks / media organisations etc. there. It is a fairly adaptable idea and the US having a large population reach actually has a lot of advantages.
Much of the research that backs all of this is already out there, so it's largely just a matter of properly pulling the most relevant parts of it together.
The approach I am trying to take with the underpinnings of this idea is a strong combination of very well proven research with a splash of strong gut instinct for something new or varied (again based on other readings, insights and similar). By adding constraints I can get focus, which can also allow a little bit of freedom at the more open end. As an example, the American Academy of Paediatrics suggests very little to no digital media use in children under 18-24 months and then 2 and above, only in a limited and quality manner – hence this idea having a focus of 2-3 years but also a desire for a high quality end result that perhaps can take some new approaches.
I imagine it might also be useful to make contact with potential stakeholders and invite them to be a part of a "critical friends" group to play out this idea. Perhaps there are variants, eg. to make it more sustainable, it could become an public / incubator platform supported by (and for media makers to feed into) Sesame, PBS, etc etc.