how remove required field from billing information into checkout I need to add a checkbox to make billing information same as shipping information in drupal 8. 
So i want remove required fields into billing address and set this information programmatically after submit the form.

But is very hard to remove required fields from billing information into checkout panes.
I also hack the Drupal\address\Element\Address.php at line 202 to set the #required attribute to FALSE but when i submit the form, i have always the message "... field is required." 

Why the attribute #required => FALSE doesn't work? Why is so hard to modify this field? Why is not there a template for this field?

thanks
You have to use hook_form_alter to changing form elements options. This field is required because very often payments modules need this data to prepare correct post variables.