Odoo-Build/snippets/mint_system.web.assets_common.set_chatter_width.xml

<data priority="50">
    <xpath expr="." position="inside">
        <style>
          @media (min-width: 1534px) {
            .o_FormRenderer_chatterContainer {
              max-width: 600px !important;
            }
          }
        </style>
    </xpath>
</data>