Is it intended in the book "Dalil Al-Hayran ala Mawrid Al-Dhaman" that the "extreme yaa'" refers to every yaa' written at the end of a word, whether it is pronounced as an alif or a yaa', and is it permissible to dot the alif layyinah that is written as a yaa' in the Mushaf?

The summary of the answer: The final ya' (ى/ي) is not dotted in the masaahif (copies of the Qur’an), whether it is a ya' or a layyinah alif (ٰ/ى). Al-Kharraz stated that the extra ya' is not dotted if it is at the end of a word, and Sheikh Al-Dhabba' is of the view that the final ya' is never dotted. This issue is broad and does not warrant disputation.