Icon Mode

Hey, i need some advice using the icon mode as i cannot find anything neither in the documentation nor in any other support topic.

I noticed i assets folder there are 3 different types of question marks to show the tooltip in icon mode, but how can i use them? As far as i can see, the qst-mark-1.png is hardcoded in index.php and i cannot find any option to set the used icon. If teher is no option maybe there is some filter i can use in my child theme to overwrite the uses asset?

I hope you cas assist with this as i would love to use qst-mark-3.png and i would change on the next update when changing it in plugin code now.