Gutenberg: How to check if a block is used in a paginated post?

There is the render_callback of the register_block_type function. In this callback, I can use add_filter('render_block', __NAMESPACE__ . '\\filter_block', 10, 2);

filter_block iterates through all blocks in my post ... until the post is paginated, and the block is on page 1, but I want to check blocks on page 3 of the post.

I found the function has_block but how to I combine this with the render_callback? The callback is only executed when the block is rendered. Is there a function for this I am missing? Like a callback used_in_post_callback or something like this?