Prolongation for a pause
المد العارض للسكون
al-madd al-ʿāriḍ li-l-sukūn
If you pause at the end of a verse, the final letter loses its vowel — but only because of the pause, not permanently. The long vowel before it may therefore be held 2, 4 or 6 counts. All ten permit all three, so the choice is the reciter's, not the reading's.
Example
ٱلْعَٰلَمِينَ
al-Fātiḥah 1:2
Stopping here, the ī may be held short, medium or long — in any reading.
By reader
All ten — 2, 4 or 6