Slide Master and Feedback Master are joined?

I was always under the assumption that these are two different entities. That one is not connected to the other.

However I am now starting to believe otherwise, and so can someone confirm this for me?

I was updating a project. Making sure the project only had 1 Slide Master and 1 Feedback Master.

I assigned the slides and layers to their correct Masters and had no issue deleting any of the unwanted Masters in Feedback Master. But upon doing the same for the slides, I discovered I was stuck with an unwanted Slide Master that would not delete, as it was reporting that the blank layout was being used 12 times.

I have 12 questions and upon checking they were all correctly allocated to the right Slide Master and to the question layout.

I realised I had my own "Invalid Answer" layer that was being used by all 12 questions. Upon checking what layout they were assigned to, I discovered that they were technically not assigned to anything. So I assigned all 12 "Invalid Answer" layers to the correct Feedback Master layout and suddenly I was able to delete the unwanted Slide Master.

So yeah, assigning layers to a Feedback Master allowed me to delete an unwanted Slide Master. Everything I thought I knew is now wrong...

Also reading this hurts my brain. I'm sorry.