Scotland's entry into the EU if they go independent is not in question, which makes the SNP's insistence on a referendum before Brexit a needless piece of posturing. Instead, both they and the EU want to collude to fuck the rest of the UK over, and make sure we suffer as much from Brexit as possible.
Putting a referendum off until after Brexit is a completey fair compromise that prevents the SNP and the EU working together to make sure the UK pays for leaving. If the SNP somehow forces the issue I would, even as a left wing remain voter want to see us take some action in retribution. For example I would totally support EU trade with Scotland being barred from travelling through England by road, or heavy tolls imposed and likewise for anything travelling through our airspace or water. I'm sure that would have consequences for us, but equally I really take exception to the SNP trying to take advantage of a delicate situation affecting everyone's lives like this. If they force the issue they can at least share in the misery.
After Brexit, fine, they can have whatever vote they like. I certainly couldn't give a fuck if they leave in the long run, in fact it might help unseat the Tories.