I am not sure what curriculum you are planning to use with parents, but there are many evidence-based curriculum out there that have proven results. In regards to online modules, Triple P has an already created online module for parents that may be helpful to look at so you don't have to reinvent the wheel.
I really like this idea of having a kit to give to a caregiver of a child 0-3 that contains activities that can be done with the child to enhance their brain development through play. Have you thought about adding activities that utilize low-cost household items such as pie plates, cereal boxes and plastic tupperware? These are items we frequently teach parents to utilize that may not have the financial ability to purchase expensive toys for their children.
I have had the opportunity to see these playgrounds be used in one of the small communities of Southern Arizona and it has been amazing. Watching the children interact with each other and use their imaginations with each of the different pieces provided in the kit is inspiring.