I’m using Jetpack, honestly, mainly just for the masonry gallery feature. But, I’m not especially happy with how few options there are for styling it. However, I do have hundreds of posts with galleries on them, so I need something that hooks up to WordPress’s native galleries and uses the native media library in the same way.
Are there any good and well supported alternatives that I could look into for this?
Are you using standard WP gallery for this ? JetPack’s gallery can be achieved in few lines of code, so it is not a great feature. But unless you are using standard gallery/ or shortcode it might be difficult to replace in all your posts.