I have recently did a full test for the rocking base lounge set.
video link https://vimeo.com/160746018
The base works well and it holds the user well. Velcro connections help to hold both pieces in place. But, this will be an item which will have restrictions for only pre sch kids 3-5 years old.
Estimated max weight limit of 30kg for the rocking base to function properly.