I've finished The Steep Approach to Garbadale and I'm a bit disappointed. Technically, the book answers all the questions it raised but I feel dissatisfied. I've put my more detailed views in a comment, so as not to spoil the book for anyone.
It did raise for me the question of which is more important: the beginning or ending of a book? Anyone who wants to get published knows the importance of a beginning to hook the reader in but as a reader I think it is the ending of books that tends to stay with me. If the ending doesn't work for me then it colours my feelings about the whole book.