I am making a door opening in a stud wall and intend to line it with an MDF liner. The plan is to leave a loose fit and pack out any gaps. I need to make the liner absolutely plum as the doors are a fixed width and height. I have already noticed that some of the studs have already bowed and twisted slightly being in the dryer atmosphere of the house hence using packers to achieve plumb.
My question is what is the recommended gaping between liner and stud?