OK a couple of weeks later I can answer my own questions.
They are IMHO unusable without runners if your bees lay down even the smallest amount of propolis.
Fitting six 'fresh' frames with foundation into a nuc for an artificial swarm shouldn't result in two or three dead bees - I'm damn sure it wouldn't if I did it in a national hive with space under the runners - it's impossible to use any finesse in lowering the frame as they are buried down a deep recess.
Unless you have tiny fingers that can grip right at the very tips, the frames are impossible to lift unless you bugger about with a J shaped hive tool (or even a pair of them) on every frame - lifting the frames with thin nitriles on was like going back to the time I used to use thick leather gloves.
The bees also propolised the frames to the lids so I've now fitted a builders plastic sheet crownboard as a temporary measure.
The bees were wax chaining in the feeder so no doubt that will be full of comb in a few days time.
How the hell I get them out of the feeder is anyone's guess! I can't see smoke working at the bottom of that deep chamber.
Just like all plastic queen excluders, its the attention to detail that turns them from bags-o-shite into something that could even be considered a workable design.
I'll use them, but I'm nowhere near as impressed with them as I thought I'd be. If I had the time I'd have preferred to have built a few 14x12 nucs out of 12mm ply.