If you loved Fate/stay night: Heaven's Feel I. Presage Flower, try Fate/stay night: Heaven's Feel III. Spring Song
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.

Fate/stay night: Heaven's Feel I. Presage Flower

Fate/stay night: Heaven's Feel III. Spring Song
What they share
Both films are directed by Tomonori Sudo, and they both carry the bittersweet, foreign gem mood tags, and they sit in Action / Animation / Drama / Fantasy / Romance territory. If that's the register that drew you to Fate/stay night: Heaven's Feel I. Presage Flower, the second film will land in a comparable space — through a different lens.
What Fate/stay night: Heaven's Feel III. Spring Song is
A trilogy wraps up with magical martial arts and a hero stuck in emotional quicksand. Shirou and Rin try to stop the Holy Grail War while Sakura’s inner darkness threatens to swallow everything—and Zouken still can’t keep his hands to himself. Someone finally gets a song that isn’t a theme.