When /filtering with -k, inside the alias called, $v1 is $null.
I would expect it to be filled since $v1 is available from pretty much any scope.
Try from any editbox:
Code:
//if (1) { write -c test test | alias fv1 echo -a > $!v1 - $!1 | fv1 | filter -fk test fv1 | fv1 | alias fv1 }

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