Indefinite article with uncountable nouns

In a comment, choster wrote:

These examples are unexceptional. Non-count nouns can act as count nouns in various circumstances, and take articles or other determiners: a love that had no equal, my strange history and our stranger future, an ochre sand to replace the gray concrete. See e.g. When can uncountable nouns be countable? and older duplicates like The article “a/an” with uncountable nouns or Usage of an article in front of the structure “adjective + non countable noun.”.

In a comment, Edwin Ashworth wrote:

Indefinite articles may be used with certain non-count noun usages in some circumstances (quite apart from countification having taken place, eg "I'll have a coffee / three coffees, please"). In 'He spoke with a great enthusiasm' the indefinite article is optional, though 'enthusiasm' cannot be considered a count usage here (*'He spoke with two / several / many [great] enthusiasms'). // This is another such example where 'a' is optional.