Hamzah is an independent consonant. At certain exceptional Qur’anic positions involving two adjacent hamzahs, the second may be pronounced with tashil—facilitated articulation instead of a fully hard glottal onset. Tashil does not mean deleting the second hamzah altogether or freely substituting a long alif.
In «ءَأَعْجَمِيٌّ» (Surah Fussilat 41:44), a special facilitated second hamzah is prescribed. The distinction between the two positions remains, but the second sound is eased. Its correct quality is chiefly learned through transmitted oral recitation.
This particular rule cannot automatically be applied to every expression containing two hamzahs. First identify the Qur’anic orthography, the adopted reading tradition and the specific rule; then imitate an expert reciter. Such fine articulatory distinctions cannot be fully conveyed by a simplified written transliteration.