G'day nysus,

"Is there a good, more perlish way of pulling this off?"

In the absence of any information about wanting to capture the deleted keys, I'd probably just do this:

delete @ta{grep !defined $ta{$_}, keys %ta};
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I'm not sure if the way you've constructed %ta is really what you intended; however, with Perl 5.30.0 I get no errors or warnings:

$ perl -Mstrict -Mwarnings -E '
    my %args = (profile => "foo");
    my %ta = %args{qw{profile user password}};
    say "BEFORE:";
    say for keys %ta;
    delete @ta{grep !defined $ta{$_}, keys %ta};
    say "AFTER:";
    say for keys %ta;
'
BEFORE:
profile
password
user
AFTER:
profile
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