Flow tuner but with playlists instead of genres

The new Flow tuner is a great step to customising the algorithm. However I rarely listen to genres or artists. I’m more of a song listener. With this in mind I think it would be cool to be able to customise a Flow mood with playlists instead of genres. 
So for example i have 2 playlists that would fall under the mood ”chill” so I would like to tell Flow to learn from those 2 playlists when suggesting music when I’m using Flow under that mood.

it might look exactly like the current genre Flow tuner where you toggle which genres the flow should include, but instead of genres you would toggle in playlist that you’ve made or that you follow.

This would give the users even greater control over the algorithm. Considering a lot of us already have curated playlists for different moods, this is a simple way of telling flow what music I listen to when I’m in a certain mood.