Quiz Success/Failure: How to use Captions instead of Shapes?

Whow, I am learning the Captivate German terminology. Textbeschriftung = caption?

This is also a very old and painful bug in the UI, where I have given up trying to have it corrected. I try to explain why I consider this to be a bug:

1.  The change in Preferences for SFH (Success, Failure, Hint) is only valid for the messages which pop up for interactive objects. They will not be applied to the feedback messages in quiz nor Knowledge Check slides.
2.  The Object Styles in the Quizzing category still have the Success/Failure captions and you can edit them, but unless you succeed at finding a very old theme which still has feedback captions in the Quizzing master slides, those objects will not be used.
3.  Quiz Preferences, Default labels still refer to Captions for the feedback messages although they are never used, it will be shapes. This is a serious bug IMO but apparently not serious enough to repair.

So far the only solution is like cheating: make the shapes for feedback look like the caption in the older projects. I see that it is 'Frosted' which has been used, correct? Not so easy to mimick in a shape. Are all the captions using Frosted, this was the Success message, what about Failure and Retry, and eventually Partial Correct?

A possibility is to create a caption with the same size as the feedback message and take a screenshot of the caption to get its 'image'. Go to the used quizzing master slides and fill the shapes with that image, you can still have the text on top. Or make the shape transparent - fill and stroke set to 0 - and put the image of the caption under the transparent shape. Once you have done this for the quizzing master slides, you can reset the master slide on existing quiz slides, and it will also be done for new quiz slides. Only possible problem: if you use Fluid Boxes in a responsive project which I couldn't detect from the screenshots.