It is my considered opinion ... that use re /flags is likley to cause more problems than it solves ...

I tend to agree, except perhaps in the context of a "shop standard" situation. (And in such circumstances, I would not feel so strongly about the issue that I would go so far as to refuse to cash my paycheck.)

Personally, I tend to go back and forth between pre- and post-Perl version 5.14 often enough that worrying about whether  '/flags' is supported just isn't worth the mental effort. This is all the more true when trying to cobble together PerlMonks regex examples.

• . matches any single character other than \n
• ...

Could not be simpler.

Actually, ". matches any single character" is simpler. Here we get into the related religious disputation concerning the uniform use of an  /xms tail on all regex operators. As you say, this is very much a personal preference. My own preference is to avoid "X always means Y (other than when it doesn't)" types of rules, especially in the highly counter-intuitive, already plenty confusing realm of regexes. As to the  ^ $ operators, my opinion, again (and in line with TheDamian), is that these should do one thing and one thing only (the /m thing), with the  \A \z \Z operators fulfilling more limited and common non-/m purposes. (As to the seniority of the latter operators, they have been around nearly for decades, at least since 5.8.8. My vague recollection is that they go back to very close to T₀ of the Perl 5 epoch, so probably at least for decades!)

These are my principles. If you don't like them, I have others.

... your assertion that it is indisputable is unfounded.

And was also intended for comic effect :)