@KCDR, I will need to do the modification next season. I had two hives this season, one starter (simplex) and one larger (langstroth). I tried the super with the frames on the larger all-langstroth population but I guess it was too late in the (mediocre) season because the girls were hardly moving up. I found the flow super box to be quite ‘leaky’ too so maybe they where not comfy enough (- or maybe I was just too soon).
That said, I prepared two flow frames with a brush of wax as I had read here, surrouned with regular foundation frames, and they where working more on the flow frames and not working out the other frames with foundation at all. I removed the super again after a few weeks to let them focus on the hive and not waste recources on the super. But I have hope for next season (in my own boxes - sorry flow but we did not have an Australian summer this year - more below 18°C than above 25 - a lousy summer). Lets get them through winter first…
@RBK, most shops do not really mention the dimensions of their flavor of Langstroth. The biggest supplier of Belgian beeshops (on- and offline) has them in 47cm only (they replied like :"duh, of course it is 47, it is Langstroth ). UK shops I contacted seem to be on 48 as well. This site also states the compatibilty problems of the Langstroth ‘standard’ http://poly-hive.co.uk/recourses/hive-types/langstroth/
There seems to be one golden standard in beekeeping : everything (material, methods,…) differs. When I received my starter on simplex after the beginners course, one of the frames I had to transfer had longer ‘ears’ that did not fit my box, that was one of my first real challenges@home as a newbee