C Programming vs most other languages is a different animal for readability and formatting, I think you hit the nail on the head when you said "Honour what is already established"
On that subject, I really dislike some of the PHP PSR formatting guidelines, it is a C style language and they have implemented some really painful paradigms
Brackets on new lines specifically get my goat, I think it's unnecessary most of the time, there are a few other things that piss me off as well but I guess it's nice to have a standard and I am just one dude who is used to doing it his way :)
I have code tidying stuff that happens on commit so I still just do it my way and then let automation handle the pedantry!
Of course, these have little to do with core PHP, but PSR-1, PSR-0/4, and large portions of PSR-2 have been widely adopted within the PHP development community. The most-debated portion of PSR-2 is, of course, the use of 4 spaces for indentation (no tabs).
PSR-12 aims to bring the guidelines up to date with the latest features in PHP 7, but I've mostly lost track of things in PHP-land since moving to a new job and burying myself in XSL (and occasionally C#).
On that subject, I really dislike some of the PHP PSR formatting guidelines, it is a C style language and they have implemented some really painful paradigms