I think the problem is not about thin indention, but about arrows. Because of them it is hard to read the levels.
I described it here. But it seems like my explanation wasn’t clear.
Here is a more simple example. This red line must be straight in order to see levels easily.
Finding a good solution for this is not simple.
I tested some options, you can see them in the post linked above.
But this problem with arrows affects not only SA and PF.
Same with reading levels in page structure.
It is very hard to understand the structure in this case.