How can the Imam alleviate the burden on worshippers during the eclipse prayer which extends for more than two hours, and is repeating its rak'ahs in the same manner as the first two rak'ahs considered an innovation?

The eclipse prayer is a Sunnah (definition). Its best description is as previously clarified in earlier fatwas. It is permissible to pray it as two rak'ahs, similar to a supererogatory prayer, or with six rukus (bowings). If the prayer concludes and the eclipse has not yet cleared, it should not be repeated. Instead, one should supplicate, seek forgiveness, or perform voluntary prayers. If the Imam wishes to lighten it, he should pray it in the manner mentioned in Fatwa (definition) 30232, reciting short surahs.