While primarily for Estonian-made content, Jupiter.err.ee is a great resource for finding foreign films with Estonian subtitles.
If you’re using the VLC media player, use the extension. It allows you to search for and download Estonian subtitles directly from within the player without having to browse the web manually. Dune Subtiitrid Eesti
For the latest installment, Dune: Part Two (2024), official Estonian subtitles are becoming more widely available as the film moves from theaters to digital "Home Premiere" stages. While primarily for Estonian-made content, Jupiter