You can create new settings (array ), for example "showConfirmCheckbox" (in App...Form application), add number of your forms with checkbox ( [2,3,6] ) and use this settings for enable-disable checkbox.
if( \in_array( \IPS\Request::i()->id, \IPS\Settings::i()->showConfirmCheckbox ) ) {
$form->add( new \IPS\Helpers\Form\Checkbox......
}