... and the only reason for it to be four columns is that you personally find it hard to read, or do you have another, more compelling argument against using 8 column tabs?
But this isn't just a reaction rooted in practicality. To me, this looks and feels absurd. It kind of hurts to read. Again, this is just my personal take.
I prefer scope indentation of any kind to render as 4 spaces, but I'm okay with 2 as well.
Yes, it was just a personal opinion.