Explain Format output specification

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/16/sql-explain.html
Description:

Hello
Regarding the Explain command's documentation:
https://www.postgresql.org/docs/current/sql-explain.html

For non-text format options (JSON, YAML, XML) there is no mention of the
expected output.
How stable are the fields inside these ? Does the name of some field liable
to change from version to version ?
Could it be possible to have at least a high level specifications of some of
the fields ?

I have a script I'm relying on that takes the JSON output of Explain with
Verbose set to true.
It then find the "Output" fields deeply (in each Plans recursively),
use "Relation Name", "Alias" and "Schema" to get the full name of the
columns and collects them all.
How susceptible is this to break in the future ?

Thanks in advance