seo – Move "back links" in different files when using hreflang

This page specifies the following:

Common mistakes

Here are the most common mistakes with hreflang use:

Missing return links: If page X links to page Y, page Y must link back to page X. If this is not the case for all pages that use hreflang annotations, those annotations may be ignored or not interpreted correctly.

So, if I want to have a URL in 10 languages, I need 10 blocks like this:

  
    ...
    
    ...
  

each one has 1 + 10 (auto + 9 alternatives).

So, only for 1 URL, I will have 100 elements.

In this way, you can easily reach the 50 MB size limit per file for multiple URLs.

Questions

  1. I can have the "back link" in a different file? (for the previous scenario: to divide the file into 10 files depending on the language => each URL will have only one item per file) Or should I keep all URLs together?

  2. Is the 50,000 URL limit counted only for the labels or also for ?