It would also create the strange situation where a British government that had just left the European Union would be warning Scots that leaving a larger union will have catastrophic economics consequences. Surely no one involved in Brexit, or who supported Brexit, can make any argument against Scottish independence except emotional ones: that the British are a nation and for that reason should stick together. That point was almost entirely absent last time around, with the unionists instead warning that leaving would be a disaster for their economy; with many of the same people then campaigning for a Leave vote.
On a personal level I prefer Scottish unionists to nationalists, probably because I know more, but the idea that Scotland couldn’t survive or even thrive outside the UK strikes me as absurd. They gave the world Adam Smith, after all, and many countries of the same size or smaller do fine; it would almost certainly have to cut spending and the size of its government, but I imagine many nationalists would be happy with that trade-off.