//Why would the EU want to 'entertain' one of the most heavily subsidised nations in the world?//
The answer to that, of course, is that they would not. But if the possibility of the UK leaving the EU was not a consideration for the Scots in 2014, why would the SNP persuade Scottish voters to forfeit their place in the EU (as part of the UK) in exchange for a possible (but unlikely) place within it (as an independent nation) if and when the EU felt magnanimous enough to allow them in?
I'm sorry, but EU membership is smoke and mirrors when Ms Sturgeon seeks a second referendum. In 2014 she sought to persuade the voters to vote to leave the UK (and hence the EU). So the possibility of leaving the EU then was obviously not an issue. Now she seeks to persuade them likewise because the UK has left the EU suggesting that EU membership is vital for the Scots. So which is it?