How to properly add custom entities in Gutenberg

So, I’ve created a custom endpoint to retrieve some post data I need to retrieve for a feature I’m building for some custom Gutenberg blocks. After reading this answer I started doing my own implementation of it. But I have my doubts regarding how, or when should I add my custom entity. So far I’ve been adding my custom entity with a custom hook in editor.BlockEdit. Here’s how it looks:

import {addFilter} from '@wordpress/hooks';
import {dispatch, select} from '@wordpress/data';

addFilter('editor.BlockEdit', 'CustomGutenberg/customEntities', ((BlockEdit) => (props) => {
  registerCustomEntities();
  // (...)
  return <BlockEdit {...props} />;
}));

const registerCustomEntities = () => {
  const {getEntitiesByKind} = select('core');
  const namespace = 'custom/v1';

  if (getEntitiesByKind(namespace).length === 0) {
    dispatch('core').addEntities([
      {
        label: 'Custom Posts',
        name: 'posts',
        kind: namespace,
        baseURL: namespace + '/posts'
      }
    ]);
  }
}

And it works just fine, but the fact that I have to be checking if the entity has already been added in an if statement on top makes me think that I may not be using the right hook/filter/function to register my custom entity. And That’s why I would like to get some more input, as the addEntities function is not properly documentated as far as I’m concerned.

Further context: Why do I need a custom endpoint to begin with?

I’ve been developing Gutenberg blocks for a while and sometimes I’ve ran into a requirement where I need a list of all the existing posts of a given CPT. So I use getEntityRecords to get that list, but usually I only need each post ID and raw title. But then I run into an issue with getEntityRecords, since it requests -and retrieves- all of the post’s attributes, making the request take a really long time when there’s a high volume of posts.