I had two objections. First, I was mapping my concept blockless of postfix conditional onto postfix loops. Postfix loops' implementation is to create a block context. This was contrary to my experience with conditionals and I had to peek at some perlguts to realize this. My other concern was the debugging tools built into perl tell me that the next() was a static "goto" into a nonsensical location and was equivalent to not executing the next at all. It turns out the static "goto" information built into next is not used - it does its "goto" behind the scenes and in a place the debugging tools know nothing of. This exposes two perl bugs. One in the core is to populate this nonsensical op_next data and the other is in B::Concise where it reports the nonsense data.
Here's a simpler implementation to show off the bug.
push @out, $_ || next for @in;