That would indeed be a good idea.
````
$msg = JText::sprintf('COM_INSTALLER_AVAILABLE_UPDATE_PHP_VERSION', $this->currentUpdate->name, $this->currentUpdate->version, $this->currentUpdate->php_minimum, PHP_VERSION);
JFactory::getApplication()->enqueueMessage($msg, 'warning');
````
The string would be
`COM_INSTALLER_AVAILABLE_UPDATE_PHP_VERSION="For the extension %1$s would be version %2$s available, but it requires at least PHP version %3$s while your system only has %4$s"`