Spoilers: Nothing specific but generally S2/3 and S6 feels.
Warnings: Speedforce being an uncaring entity, but not deliberately in the same way people would be. Unbetaed and liable to be on the poetic side of prose.
Also inspiration from the song "Suspirium" by Thom Yorke which I listened to on repeat while writing this.
What we ask of you (you already gave)
There are so many faces they wear. So many ways to appeal to those they need. No one person is the Speedforce. Everyone lives, everyone dies. Some stay longer, some shine brighter no matter how short their time intersects with Barry Allen's. It's always hard to judge who matters, and why, when so little differs in the big picture. They try combinations, finding who is right in some instances, not in others. Simulating responses.
No one time is more meaningful than another. Every conversation carrys a weight hard to bear – a force that is amplified by motion through a timeline they see the entirety of - and they cannot judge what is enough, too much, or just so at a single point. This person matters, as a whole, a discrete unit – that person will set him off in a direction, but when it works is harder to pinpoint.
Each time the Speedforce tries, they watch carefully, see a new face they cannot fully understand. Because Barry's reaction is never the same, no matter who they call upon. Every choice they make creates something they can't fathom until afterwards. One Barry makes the right choice, one makes another.
They recognize patterns, but all they see is effectiveness. Not impact, past what works. They see the whole, the flow of this to that, the symmetry so desired. They see what is best without caring how. More anger isn't a problem. unless it tugs at the negative Speedforce. More sadness has a utility up until a line crossed where he will not budge. They ask and ask and it is never too much. Until that moment he breaks and is torn asunder, unexpected, a deviation incalculable. It falls apart. Moment by moment, and instantaneously. Then they understand fear, all at once.