Scots Independence Referendums

Tom Harris has an interesting view on the SNP and the possibility of another Scottish referendum.  I think he correctly diagnoses Sturgeon's dilemma.  However, it is striking how very different different referendums are treated.  The EU referendum is treated as a once and for all existential choice.  The English mayoral referendums were simply ignored no questions asked and the four devolution/independence referendums of 1979, 1998, 2014 and whatever date may or may not be chosen next, fall somewhere in between.