The first final Tikkun is at the third Aleph-Sofit, at טצ"ץ אאאצצץ"ץ. This is when the count of Arich Anpin reaches seven. This is in agreement with the penultimate Tikkun of the Ramchal's Tikkunim Chadashim, regarding י"ג תיקוני דיקנא דז''א.
At a deeper level, the 13 Tikkunim culminate at the third Samech, which is after seven Tikkunim of Atik Yamim.
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