It would be very popular move for every EU politician to fast track Scotland to EU. But yes, it would be complicated to separate from UK and become independent. Becoming EU member would not be that complicated.
And we have "God's Own Country"[4] which is a phrase but does have an independence movement[5], and a region (Mercia) which hasn't been a place since 527-897CE but still has an independence movement[6].
[1] https://en.wikipedia.org/wiki/Black_Country
[3] https://en.wikipedia.org/wiki/West_Country
[4] https://en.wikipedia.org/wiki/God's_Own_Country#Yorkshire
[5] https://i-yorkshire.com/yorkshire-independence/
[6] https://independentmercia.org/declaration-of-independence/
But all that was at its apex years ago now it’s more stable.