Howdy!
The issue with adding weight dynamics to the game is that it would massively increase its scope, require variants of hundreds of scenes, etc. There will definitely be more weight-gain content, and blueberry stuff is absolutely planned, but they'll be relegated to La'ard, just so it all remains manageable to develop.
In the future, though, I want to work on a project that explicitly does away with these "content islands". They bug me quite a bit!