Hello Junior,
I think you don't understood what I try to say (my english is not good :) )
in a form with multi stages, each time you click on next, the form is saved.
You define on which stage each fields are available with the option 3 "Stage"
So to have access to a field on each stage, you must have an alias of this field in each stage.
Knowing that an alias of a field is a field with the same storage of the original.
It's something which is working well, and that we use often, so if for you it's not working, it's probably due to the storage of your differents fields.
Regards.
Lionel