Thanks for taking action.
As you're already working on this matter would it be possible to extend it a little bit
$TYPO3_CONF_VARS['SYS']['displayErrors'] = 'what I need';
https://docs.typo3.org/typo3cms/SecurityGuide/GuidelinesIntegrators/GlobalTypo3Options/#displayerrors
and integrate something "more"

$TYPO3_CONF_VARS['SYS']['devIPmask'] = 'my ip';
https://docs.typo3.org/typo3cms/SecurityGuide/GuidelinesIntegrators/GlobalTypo3Options/#devipmask