Thanks for the reply @dclin 
Yes I suspect it’s something to do with that, maybe the fact that it’s a custom env: flex environment which costs more money – regardless that it’s constrained to 1.
And just another small point of confusion for me, what do you mean: “causing the container to be up the whole time”? How could the app be running if the container wasn’t up? I know streamlit cloud puts projects to sleep after some inactivity, but then what’s the point of paying for a service if it’s not up?!