That’s something like what we had in place.The surprise comes from the intense focus that we humans tend to have when changing things.
e.g. the couple of times that changing my defaults bit me, it was because I was changing the defaults with a particular subset of my goals firmly in mind. I inevitably forgot about other goals that shouldn’t be changed in that same way. This was made worse by the fact that we’d conflated reminder and other goal settings, and by the fact that I’ve currently got 40+ Beeminder goals…
One thing that @dreev proposed in the daily beemail was to put an apply defaults button on each goal, possibly exactly where you’ve described, so that it’s easy to copy ‘universal’ settings when that’s the right thing for your goals.