grammar - Can an adverb be a noun?

I have seen this post for the answer to my question, but this is not much help in case of the question I am going to ask.

Here is an example sentence -

The new design of Twitter profile is more of a Facebook profile than never before.

than here is a preposition, there is no doubt about that. But before after than acts like a noun. But from dictionary entry against before doesn't say it's a noun.

So what is the explanation?

Answer

'[T]han here is a preposition, there is no doubt about that.' [OP]

and

'A noun is the only part of speech possible after a preposition'

and

In the accepted phrase 'better than ever before', 'ever' cannot be a noun.

So we have a contradiction. The only question to address really is how many of the above assertions are not true?

If we look at

'It is better than [it] ever [was before]

we find a construction which presents no problems. Here, 'than' is a conjunction; there is no doubt about that. 'Ever' is an adverb.

But in the ellipted version, 'than' is now an ex-conjunction and 'ever' is an ex-adverb. In other words, forcing traditional analyses on elliptical structures will lead to extra-grammatical analyses (ie 'the rules' will be broken).