Is the muezzin's post-prayer supplication: "O Allah, help us to remember You, to give thanks to You, and to worship You well, and do not make us, O our Master, among the heedless regarding Your remembrance or Your obedience" an innovation (bid'ah), especially since the latter part, "and do not make us, O our Master, among the heedless regarding Your remembrance or Your obedience," is added to it, and the mosque imam believes it is not an innovation, and likewise for saying: "Allah, Allah, Allah"?

The statement of the muezzin, "O Allah, help us to remember You, thank You, and worship You well," is prescribed. However, adding to it, such as "and do not make us, O our Master," is not prescribed and falls under the category of an additive innovation (bid'ah idafiyyah), because it makes something that is not part of the Sunnah appear as if it is.

And the Imam's statement that whoever does not understand the religion prohibits what Allah has made lawful is incorrect, because the Sharia closes the doors to innovations and newly invented matters. And repeating the majestic name "Allah" is not prescribed, for the prescribed dhikr (remembrance) is a complete and beneficial statement.

If you have sufficient knowledge, advise the Imam; otherwise, simply pray for his guidance. If it is possible to replace the Imam with another or to pray in another mosque, that would be preferable.