When you apply this changes to the whole system, upper logic is not suitable. It would be better to hack the core. However, it is necessary to apply these changes again when the core is upgraded.
Hacks:
1. Add below function in to the qa-include/app/users.php
function qa_user_level_html($level) {
return '<span class="qa-user-level qa-user-level-'.$level.'">'.qa_user_level_string($level).'</span>';
}
2. Grep(Search) under qa-include with "qa_user_level_string" string.
3. Replace from "qa_html(qa_user_level_string(...))" to "qa_user_level_html(...)".
Core developers might merge these changes into the core.