EmulationStation removes non-default metadata tags in gamelist.xml

[hiulit]

I've created my own scrapper for Godot games and I'm adding some extra metadata of my own, like game-source, id, and api-source.

When I play the game, everything that's not on this list https://github.com/RetroPie/EmulationStation/blob/master/es-app/src/MetaData.cpp gets wiped out.

Here's an example:

Before:

<game game-source="https://securas.itch.io/daemon-vs-demon">
  <id>197731</id>
  <api-source>itchio-godot-scraper.now.sh</api-source>
  <desc>A hack and slash roguelike winner of the 2017 Github Game Off Jam</desc>
  <developer>securas</developer>
  <genre>Role Playing</genre>
  <image>./images/Daemon vs Demon.jpg</image>
  <name>Daemon vs Demon</name>
  <publisher>securas</publisher>
  <rating>4.4</rating>
  <video>./videos/Daemon vs Demon.mp4</video>
  <path>./daemon_vs_demon_linux.pck</path>
</game>

After:

<game>
  <path>./daemon_vs_demon_linux.pck</path>
  <name>Daemon vs Demon</name>
  <desc>A hack and slash roguelike winner of the 2017 Github Game Off Jam</desc>
  <image>./images/Daemon vs Demon.jpg</image>
  <video>./videos/Daemon vs Demon.mp4</video>
  <rating>4.4</rating>
  <developer>securas</developer>
  <publisher>securas</publisher>
  <genre>Role Playing</genre>
  <playcount>1</playcount>
  <lastplayed>20200806T180018</lastplayed>
</game>

Is there any way to keep those extra tags?