I like idea with ready with fill and shake, but my vision looks like:
you got 3(or more) small bottles, with wide neck preferably, and you split you daily meal in them equaly - so you dont need use the scoop, because there should be same amount in each bottle. when needed, just fill shaker from powder bottle plus water and you totally ready to eat it.
I think about it, because I dont like grab meal with scoop, when daily package half empty.
And its also will be plus for bulk packaging, because you dont needed to put in trash one packet every day.