Changing Block Category Position

You can change the block category position using the PHP filter stackable_block_category_index.

By default, the Stackable block category is loaded first in the block inserter list (index 0), but can be changed by adding a PHP filter like this:

add_filter( 'stackable_block_category_index', function( $index ) {
    // Change the Stackable category to be the second one.
    return 1;
} );