I think it is important to note that shift is also destructive, so using that as the idiomatic control of the experimental feature shows that processing it the accepted way more often than not also results in @_ not being populated.

This doesn't apply to another idiom (that I even use some times) that are non-destructive - like, my %opts = @_ - assuming params are passed in like foo(param1 => 2, param2 => 'foo').