Preposition usage and more/most usage [closed]

Preposition Query

It is correct to say "According to" example sentence:

According to ChatGPT, “with” is the answer.

So is it ever acceptable to say "in accordance to" ? Like in this example:

The decision was made in accordance to the recommendations of the independent review.

ChatGPT stated that it can only be "in accordance with" , which I agree does sound correct, but is "in accordance to" actually incorrect or is it acceptable?

more/most Query

Example sentence:

The second proposal is by far more convincing than any other proposal that was presented.

I believed that "more" would be correct in the sentence above because we have the word "than" and are comparing two singular nouns: "" and "any other proposal" (just like "every", the word "any" is singular)

However, ChatGPT stated that "most" would be acceptable as well. I'm guessing it could be "most" as we are kind of comparing it with all the other different proposals.

Would it be better with "more" or "most", or are really both acceptable?