Here I am, probably too late again.
Before cutting my doors, I pre-prepared the stiffeners as much as I could.
Then, I cut out one door and within minutes had the stiffener clamped and glued with the thickened epoxy. Once satisfied, I cut out the 2nd door and did same.
To date, both doors have been true to the original angle. I did store them indoors, vertically on their sides until needed.
It sure beat trying to glue stiffeners before doors were cut.