There aren’t many exterior doors in a house...there aren’t any reasons for making a mistake in budgeting and ordering them.
We create worksheets that list every exterior door separately, with prompts for you to add you spec’s as to type of door, sills, bores, exterior trim, etc.
We are careful in checking for 6 9/16” jambs, outswings, options, and situations where floorplans and elevations do not agree.