Firewall set up causes 500 error

The lines added at the very top of the wp-config.php file for the firewall are not compatible with some hosting providers that also insert custom lines into this file.
For example, Kinsta adds custom instructions, and since AIOS doesn’t include a closing PHP tag in its code, it results in a 500 error.
The issue can be fixed by manually adding a closing ?> tag after // End AIOWPSEC Firewall.
But it’s a bit annoying to have to do this every time…