So how do you apply it selectively? The flags that turns these things off and on work on a line by line basis, which is not the level of resolution you’re referring to. The article mentions clang-format. It doesn’t allow mixed formatting, does it?
Indenting a block correctly seems like a trivial reason to auto-format a source file. Between text editors and the person at the keyboard responsible for creating logical things, committing incorrect indent would seem easy to avoid.