Context: How does \Magento\Framework\View\Model\Layout\Merge::_loadFileLayoutUpdatesXml() work?
\Magento\Framework\View\Model\Layout\Merge::_loadFileLayoutUpdatesXml()
Details: How are the app/etc/config.php and app/etc/env.php files loaded?
app/etc/config.php
app/etc/env.php
See also:
<sequence>
module.xml