Only submit default values for hidden fields in fieldsets if those fieldsets are visible

In the new Forms 2.0, by default all hidden fields will submit their default values, even if they are in fieldsets with visibility rules and those fieldsets aren't visibile when the user submits the form.

Wouldn't it be cooler if those values only submitted if those fieldsets were visible at the time of submission?
 
That way if you want it to submit conditionally, put it in that fieldset. And if you want it to submit by default no matter what, put it at the root level (outside of any fieldset).