It's easy to fix - move use Moose; to before no warnings 'experimental::signatures'.
The signatures feature is experimental at /opt/perl-5.28.1/lib/site_perl/5.28.1/OpusVL/SysParams/Manager/Namespaced.pm line 101.
The signatures feature is experimental at /opt/perl-5.28.1/lib/site_perl/5.28.1/OpusVL/SysParams/Manager/Namespaced.pm line 125.
The signatures feature is experimental at /opt/perl-5.28.1/lib/site_perl/5.28.1/OpusVL/SysParams/Manager/Namespaced.pm line 130.
The signatures feature is experimental at /opt/perl-5.28.1/lib/site_perl/5.28.1/OpusVL/SysParams/Manager/Namespaced.pm line 138.
The signatures feature is experimental at /opt/perl-5.28.1/lib/site_perl/5.28.1/OpusVL/SysParams/Manager/Namespaced.pm line 141.
It's easy to fix - move
use Moose;
to beforeno warnings 'experimental::signatures'
.