How the open :utf8 pragma works in perl - in relation to CPAN modules?

I'm already read thru the next:

• Perl Unicode Cookbook
• How differs the open pragma with different utf8?
• How to use utf8 encode with open pragma
• Does the autodie-pragma have influence on the encoding?
• many others... (like: perlunicode perluniintro, perlunifaq, perlunitut)... ;(
• and of course tchrist's geniue answer Why does modern Perl avoid UTF-8 by default?

but probably missed some BASIC points.

Using the

use open(:utf8);

Affects cpan modules too? E.g. when some CPAN module opens any file, it will be opened with :utf8? Is this statement TRUE? (or the open pragma is only lexically scoped?) AFAIK - it affects modules too, but in "inconsistent" way.. (probably it is a problem of the modules).

Have the open pragma effect to opendir? - what i already tried - no - i still need extra decode on all filenames coming from readdir (in addition to NFC). So, IO::Dir is something different - what open pragma doesn't covers?

Affect the open pragma sockets, pipes too? (e.g. anything what is a sort of IO::Handle ?)

All (or most) CPAN modules knows when doing i/o how they need to do it (utf8 or lattin1 or raw?) (probably not, because a simple autodie doesn't works with the open pragma... :