"... the need to use local::lib.

I don't have local::lib installed under Cygwin -- I don't have any need for it. I checked this with a utility, perlmodver, that I wrote to provide info on installed modules -- here's an example:

ken@titan ~/tmp
$ perlmodver local::lib Data::Dumper Data::Dump
NOT FOUND: local::lib
----------------------------------------------------------------------
+--
Data::Dumper 2.189
  in /home/ken/perl5/perlbrew/perls/perl-5.40.0/lib/5.40.0/cygwin-thre
+ad-multi/Data/Dumper.pm
----------------------------------------------------------------------
+--
Data::Dump 1.25
  in /home/ken/perl5/perlbrew/perls/perl-5.40.0/lib/site_perl/5.40.0/D
+ata/Dump.pm
----------------------------------------------------------------------
+--
[download]

The code, if you're interested, is in the spoiler. I have copies of this on many platforms and use it frequently.

ken@titan ~/tmp
$ cat `which perlmodver`
#!/usr/bin/env perl

use 5.014;
use warnings;

die "Usage: $0 module [ module ... ]\n" unless @ARGV;

for my $module (@ARGV) {
    eval {
        eval "require $module;";
        die if $@;

        my $mod_ver = eval "\$${module}::VERSION" // '$VERSION not set
+';
        say "$module $mod_ver";
        say "  in $INC{qq{$module.pm} =~ s[::][\/]gr}";
        1;
    }
    or do {
        say "NOT FOUND: $module";
    };

    say '-' x 72;
}
[download]

"... I don't like having two home directories ..."

Same here; except I have more than two:

• C:\Users\ken
• /home/ken
  aka C:\cygwin64\home\ken
  aka /cygdrive/c/cygwin64/home/ken
• Plus multiple archives from old machines all containing ken/ directories.

I don't use Win10 directly that much; however, when I'm downloading something it typically starts by suggesting a location like ken/some/path/ (i.e. chopping off the important part at the start of the pathname). This use to annoy me intensely -- after many years of usage I've become use to this and have stopped letting it bug me.

My more normal usage is to start a shell. There's no real problem here as it puts me in my Cygwin home directory:

ken@titan ~
$ pwd
/home/ken
[download]