Eid prayer behind non Hanafi
How would a Hanafi pray the Eid prayer behind an Imam who does 12 extra takbeers? Answer: ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﯿﻢ In the name of Allah, the Most Gracious, the Most Merciful
It is permissible for a Hanafi to pray behind an Imam who does more than the six extra takbeers (e.g. Shafies do 12 extra takbeers in contrast to Hanafis who do 6 extra takbeers). According to the scenario you mentioned, you should follow the Imam you are praying behind and not oppose him with regard to the number of takbeers.
Raddul Muhtar: v. 2, p. 172-173 (Darul Fikr); Fatawa Hindiya: v. 1, p. 151 (Darul Fikr)
Only Allah knows best
Written by Maulana Mohammad Ahsan Osmani Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham