Scotland leaving the UK would be even worse than Brexit. Scots would not like the resulting economic situation, and few would like the border (and there would have to be one if Scotland has EU free movement but what remains of the UK does not). Nobody wants a change in Northern Ireland and there could be simple checks on arrival in Britain.
But Scotland has a well-defined, uncontroversial, and much shorter border
on the same island, resulting in easy access to large cities in England & Wales.
The SNP might pretend like a hard border could never happen, but it could happen. Northern Ireland is a very special case with many people who feel Irish exclusively, and it's also a long, curving, meandering border. In fact it's much longer than it has to be because of the curves around Fermanagh in Northern Ireland and Monaghan in the Republic for example.
It'd really be unfortunate for one of the world's few real multinational states to break up, and indeed a margin of over 10% ensured it wouldn't barely over 2 years ago. I understand that this is a huge change in circumstances, but almost no place on Earth would allow another go just like that. If the majority the last time holds strong, then this should be the last independence referendum for a very, very long time, as no change in circumstances will likely
ever be as significant as leaving the EU, not to mention Labour will eventually get a clue.
I'm not even dwelling about the past, rather there are huge,
current ties in trade and the movement of people that would be damaged irreparably by Scotland leaving. Scotland leaving would be much worse than Brexit,
for everybody. How do you replace that enormous amount of trade that Scotland does with and needs more (due to population and level of diversification) than the rUK? The EU can't replace the rest of the UK, which Scotland trades with multiples more, no matter what an opportunist would say about, well, opportunities elsewhere. In fact it sounds similar to Brexit....thinking you can replace that kind of trade overnight is foolishness, and that goes for everyone, and certainly the Leavers who caused this whole mess.
What about Trident? What happens in Northern Ireland...etc. The UK breaking up would not be fun, a new Scots Pound would not be pleasant, and this whole mess could easily have been avoided. If anything the EU was good at essentially disabling independence movements, as they could be block from getting in the European Union for a very long time, if ever, by any member, which encourages unity in member states. It's really ironic.