The Scottish Growth Commission – remember that? The former SNP MP Andrew Wilson's report was hailed as a triumph of realism and responsibility by economists like Professor John Kay. Sir Tom Devine, the nations' most treasured historian, thought that it could have made all the difference in the 2014 referendum. But it seems it will not even be debated at the SNP's crucial October conference.

Some of us weren't quite so complimentary, of course. The economic orthodoxy upon which the Growth Commission was built – balancing the books through public spending restraint – bore an awkward resemblance to the belt-tightening policies of George Osborne after 2010. SNP left-wingers, like the former MP George Kerevan, were dismayed that the Commission failed to recommend an independent currency, leaving Scotland chained to the interest rate policies of the Bank of England for the first decade of independence.

The document largely endorsed the claim by Unionists that an independent Scotland would be born with a headline £13 billion deficit. Labour called it “austerity on stilts”. The economic blogger most Nationalists love to hate, Kevin Hague, put the tin hat on it by wholeheartedly embracing the Growth Commission's analysis. The Institute for Fiscal Studies then commended the SNP's new realism, while predicting that it would mean another 10 years of austerity.

However, since its publication, I have to admit that Andrew Wilson's report has had some positive political impact. It does seem to have attracted interest in independence from the business community, who are at sea over Brexit and looking for answers. It probably reassured Scottish pensioners and home owners worried about the inflationary risks of independence. The report certainly won praise from Wilson's many friends in the media, and earned the SNP a deal of favourable coverage, which isn't to be sniffed at.

But as far as independence is concerned, the SGC hardly shifted the dial. It wasn't an inspirational programme and nor was it the SNP's Clause 4 moment. It didn't lead anywhere. The SNP has succeeded in repudiating the compendious 2013 Independence White Paper, “Scotland’s Future”, while offering nothing very positive in its place – at least in terms of a rallying cry. Nor can it just be ignored: it was never intended as a disposable discussion paper. The Growth Commission will be the great woolly mammoth in the room at the SECC in October. It is bound to surface one way or another.

The puzzle is why it saw the light of day at all. Why offer a whole boat-load of hostages to fortune on the eve of an expected referendum campaign? The optimistic Keynesian 2013 White Paper, for all its faults, was a successful campaigning document, not unlike Labour's 2017 General Election manifesto. It took Yes to the very brink of victory. Why did Nicola Sturgeon authorise the publication of its antithesis at the moment she is trying to build support for another crack at independence? At the very least the Growth Commission has created a rift in the movement when you would expect her to be seeking unity.

Well, one heretical thought is that the Commission was never intended to kick-start a campaign, but was part of the process of building down expectations of an imminent referendum. It was as political downer, a dose of Tramadol to quell the delinquent spirits of indyref enthusiasts, who believe that independence is a matter of political will, inspiration and taking politics to the streets.

Nicola Sturgeon has shown no sign over the summer of preparing for independence. Back when the 2013 White Paper was published, the SNP staged high-profile conferences around Scotland bringing together the disparate elements of Scottish civil society – not just SNP members – to debate its contents. I remember this because I was asked to chair one of them. There's been nothing like that this time, only internal party discussions.

Some Nationalists are beginning to wonder whether Nicola Sturgeon really wants a referendum at all in the near future. The SNP is supremely powerful in Scotland, with Labour in confusion and the Conservatives discredited by Brexit. Why would she risk all that on a throw of the dice? Was she so burned by the last attempt at a referendum, losing a third of her MPs, that she's lost faith in referendums?

The SNP's objective is, of course, independence, but political parties are first of all about getting and retaining power. About keeping bums on seats. Losing elected members, MPs and MSPs, is painful: it means close friends losing their livelihoods. The party is still in mourning for the casualties of 2017– like Angus Robertson and Alex Salmond.

There would, of course, be dismay in the party if Sturgeon were to shelve independence again in October. This is likely to be the most divisive SNP conference since the rows over devolution in the 1990s. But Nicola Sturgeon is not in any political danger. There is no conceivable rival in the cabinet. Potential dissidents like the deputy leadership contender, councillor Chris McEleny, are remote from Holyrood politics. Nor are there organised dissenting groups in the SNP – no “Mandate Group” or “Independence Research Group”. Perhaps there should be in future.

Moreover, there will be a lot to distract the troops in October. The Tories are deeply divided and Theresa May will be lucky to survive. If she tries to breathe life into the Chequers compromise she will be roasted by the legions of hard Brexit Moggists. If she abandons her White Paper, and gives in to No Deal Brexit, there will be a huge public outcry and further resignations.

Over at Labour, the row over anti-Semitism looks set to dominate the conference, but not in the way Jeremy Corbyn’s MP critics hope. The Labour leader's many admirers in the party, who believe none of it, will use the conference to push for mandatory reselection of MPs to clear out the right. This could split the party.

Coming last allows Nicola Sturgeon to focus the SNP conference on not being Labour, or the Tories, but instead being the leading Remain party. She may not actually endorse a People's Vote, but she could say that a No Deal is unthinkable and that Article 50 should be delayed if there is no agreement on Britain's future trading arrangements with the EU. Opposing Brexit will crowd out discussion of indyref2

So, if the Growth Commission was a way of levelling with party enthusiasts – of saying that the economics just aren't right for independence at the moment – it would make some political sense. The risk, of course, is that it might be too successful, and make it very difficult to reconstruct the 2014 coalition in future. The Yes campaign managed to galvanise voters in working class communities who had largely given up on electoral politics. Voter registration in 2014 was 97 per cent and turnout on the day was 85 per cent.

It would be hard to build that kind of engagement on a programme that has spending constraint as its core economic strategy. However, a dose of “economic realism” might consolidate the SNP’s hold on Holyrood. We may he seeing the beginning of the end of the SNP as a radical, insurgent party, and the birth of what might be called New SNP.