but I do not believe that assembling your own style by considering various options and choosing those which you consider to be the best for you would be CC
Definitely. That's why I said "the real question is whether the style was created with thought".
they all come at the expense of changing the regex semantics to be different from the standard/default semantics.
"standard/default"? They're not the same. Personally, I use the modifiers only when needed. I need s more often than not, so my standard usage is with s, which is not the default. From what I see, when people don't use s on a regexp that uses ., it rarely would cause no harm to use s, and it's often an error not to use s.
When there are defined standards and well-known semantics, I find it much better to stick with them where possible and only deviate when needed rather than making deviation the default.
When there are defined standards and well-known semantics, I'd love to here about them. There's obviously differences in the standard usage of the modifiers (default vs Damian's, for example), and the semantics are far from constant.