It sure makes sense to me, thank you! I'd have to use shift instead of pop to keep the elements in the order they appeared in.
What I ended up doing is very similar to what you proposed:

    if ($collecting) {
        push @event_queue, sub {
            $self->SUPER::start_element($xml_data);
        };
    }
[download]

then, later on I empty the queue by executing the closures:

    foreach (@event_queue) {
        &$_();
    }
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