Great point about the value of seeing the rate when setting breaks!
And smart points about how tricky this is to get right.
We need to get this puppy out the door so let me propose the minimal possible thing for now that should be slightly helpful without requiring more agonizing or fussing with the UI:
Hovertext/tooltip on the “set the weekly rate to” field like so:
Final ${FREQ}ly rate: $RATE
(I think @adamwolf is the one to implement this and should feel free to put it after the rate field instead of as hovertext if it fits fine and looks good without fussing, or if he thinks of an alternative to final rate that will be more helpful than final rate without ever being misleading. Mainly I’m anxious to do the easiest possible thing for now that lets us call this feature good enough to ship! (I mean, it’s already kind of shipped, just not officially and not linked to anywhere in the UI. You have to know to go to beeminder.com/breaks currently.))