This is another big one for me: the flow of data quickly becomes unmanageable, especially for non-technical users. I’d like to see things like local variables and (global) constants, for example to share a Google Drive folder ID across flows.
Flow-scoped storage tasks can be (ab)used as local variables, but it’s often tedious and/or counter-intuitive to use. (For example, using the result of a “Put” task as an input for something else.) I’d love to see a dedicated system for this that’s easier to manage, maintain and takes up less valuable screen real estate.
(Again, I’m still working on formulating some more coherent thoughts and suggestions!)