In principle, the citizens of any nation should be able to determine their future by means such as referenda, elections, etc. But the problem with a Scottish independence referendum is “Who gets to vote ?”. Scotland is part of the UK, so any referendum is really all about breaking up that nation. That will affect everyone in some way, so logically all citizens of the nation should get a vote, not just the small sub-set who happen to live in one part of it. So by all means have another referendum, but only if all British citizens get a vote. That should also satisfy the Scottish diaspora who were a bit grumpy because they didn’t get a vote last time. Doubt it’ll happen like that though !
And given how difficult B****t is proving, just how hard would it be to separate the Union ?