I admit that I find it difficult to translate the meaning of ‘sensory-friendly’ into the necessary conditions for the playground, but your suggestions are a much better choice of keywords. Thank you for your understanding. 

By the way, are you familiar with the wiki (https://wiki.osm.org, including https://wiki.osm.org/wiki/Tag:leisure%3Dplayground) and/or the forum (https://community.osm.org), where you can also find and detail suggestions and ideas for mapping possibilities?