I've been looking into this and just got some clarification from TimToady on expected behaviour for adverbs and chains in general ( http://irclog.perlgeek.de/perl6/2016-06-02#i_12589974). The gist is that adverbs should be placed at the end of a chain and then distributed to all the operators in the chain, which will of course make the example in this ticket "just work".
Dan
