The ability to impose a context on a group of selected fields.
It's a commonplace where we will build a UI and then repurpose this UI metaphor throughout a solution. Currently we need to go through each field and change the context one by one. Since FM already "knows" the field if you choose a new context when the base table does't change, it seems to reason that you should be able to change the context globally for those fields that are going from one context to another.
Obviously, if there were fields in the group that are from a different base table a warning would need to be issued and then those would be "missing" after the action.
Not a large bore idea. It does however, reinforce a design pattern that we find powerful. Build encapsulated UI (typically in a popover) that can be re-used. Quasi objects if you will. No inheritance in the big sense but in a sense:-))
This would be a great time saver for developers.