A little background: in Brazil drywall is kind of novelty yet, mostly used on comercial building. Houses here are still built only using bricks, with the jambs of door being affixed to the bricks either using PU foam or nails on wooden blocks lodged in the brick wall.
My house will have exterior brick wall (16 cm thick) with interior drywall (9 cm thick).
The exterior door jambs should be affixed to the bricks or to the drywall studs (metal studs here) or both?
What are "extension jambs"?
I was thinking on installing first the door on the brick wall and after that install the studs and hang the drywall and in the end install trims and any additional jambs, etc. Is that feasible? How should it be done?