Quotes from link above (http://derekbateman.scot/2016/04/17/rise-with-ukip-anyone)
Basically I agree with this -
"
The truth is that nobody knows how many votes each party will get on the first ballot which determines how many seats they win and adjusts the calculations of the second votes. It is a blind gamble and if you get it wrong, you may help a different party. But that’s the serendipity of democracy. (It’s also why we need to look at changing the system. When people don’t know how it works or what to do, even in the best informed electorate, we’re in trouble).
"
And this -
"
So if your objective is to make devolution more attractive and more fun, give your second (of your first) vote to smaller groupings who’ll make Holyrood appear more consensual. I used to agree with that.
"
But not the next sentence -
"But if it’s power you’re after to cast off British control and imagine a renewed nation, you invest in the one party that can achieve that – without qualification and caveat. (I could almost get Professor Curtice to agree…)
"
There are people who want Independence but would rather it was not under (at least as the sole party) the SNP.
The party line of both the Greens and RISE is pro-independence, so voting for either is still (partially) a 'vote with future independence in mind'.
BUT (unless there is a UK Brexit vote - quite possible but harder to guess than the current Holyrood result, in which case who knows!!) there is unlikely to be IndyRef2, in the next 5 years and there still needs to be some sort of opposition to the SNP and MSPs who have ideas that are different from the SNPs and the willingness and ability to alter the Gov's proposals (a stronger committee system would help).
If people are convinced supporters of the SNP and its policies (no manifesto yet), then it is perfectly reasonable to vote SNP twice. If people would like a better/different Scotland from the SNP vision, then it's reasonable to vote for another party even if they place a constituency cross for the SNP as well.
I suspect there are some Green supporters/voters who would have voted SNP/Green but are now wondering whether to in the face of the '2 votes SNP' calls.
At the last Westminster election (results distorted by FPTP) there must have been plenty of people who voted No in the IndyRef and then SNP, but are still not sure they would vote Yes in any future IndyRef.
I'm sure this time there will be people who vote SNP and also Lab or Tory because they are voting for the 'best' Gov/opposition - not just 'to show support for some future constitutional change'.