Whilst my favoured advice would be to make your own original sky photography library. Within the Sky image options provided, there are many different sky ‘moods’ to choose from for most occasions. Plus as a X Member you get extra resources, tips, and other useful photography and editing utilities.
Luminar AI 2 deals with one of the perhaps most common irritations with Sky Replacement, the gaps that sometimes appear where merging with intricate items such as trees and hair, for example.
Besides this time saving improvement, you’ll have more control of aligning your imported Sky.