Her majesty will have to pour a glass of scotch brew and toast to the proponents of a scott/english border, that will obviously not happen she is part of that 60%.60% of Scotland's goods being exported to the rest of the UK, a hard border would be unworkable.
the only way is for scotland to adopt a digital currency ( scott bitcoin) and build a banking system detached from the sterling , afterall 75% of the scott economy is service based.