The political ramifications are identical - it's not a technical issue. Spain is desperately afraid of Catalonia departing - and the nuance of 'we left the EU

The political ramifications are identical - it's not a technical issue. Spain is desperately afraid of Catalonia departing - and the nuance of 'we left the EU before we joined' won't matter to the voters. Scottish separation and ascension to the EU would carve a crystal clear path for Catalonian separatists, and give massive wind to their sales. To the above commenters point - no gov will likely ever come out and say it, but there's no reason for Spain to support Scottish ascension, and every reason to be against it.