Why membrane is glowing at the video, if there is no plasma discharge as you're saying?
This is indeed a good insight and a question. The story of this finding is, it has been accidentally revealed by Russian expert working in research of desalination technology in Dubai, who attempted to increase the speed of desalination process with external electric voltage introduced onto a membrane. He wasn't successful with it - but he observed an anomalous heat production instead. I believe that the overunity effect is the special result of narrow membrane pores, which would force the water molecules to reorient itself and to collide in one-dimensional manner within nanopores. My theory is, an avalanche-like effect analogous to famous Astroblaster toy is what it applies there and what amplifies the amount of heat produced due to repeated breaking and recombination of water molecules. In this extent the reading of anomalous heat during hydrogen recombination may be of certain interest there. I therefore think, that this device may not run on principle of cold fusion, as its source implies.
If the plasma would be the actual source of anomalous heat, then no special osmotic membrane would be actually necessary and every cheap porous membrane or sintered glass filter could be used instead, because the heat would be formed across plasma layer above and bellow the membrane - not within pores of membrane and the type of pores or membrane will be irrelevant. The ceramic membranes would be more stable and as such more suitable in this type of reactor after then. The video source says, that the osmotic membrane survives just an half of hour in the experiment, after then the heat production ceases down and the membrane must be replaced. This could serve as another indicia, that the heat production actually runs inside the pores - not within plasma outside the membrane - but this assumption should be still subject of future research.
The plasma electrolysis at electrode is commonly used in cold fusion research, but its energy yields aren't as high in general. What I think is, that the plasma has been demonstrated at the end of video when the water was already boiling. Under such a situation just a small amount of heat will be able to form vapor layer above membrane, which would get ionized with glow discharge. What I therefore think is, that the plasma formation is actually an unwanted artifact, which would decrease the energy yield and life-time of membrane - but I can be indeed still wrong. IMO it would have a good meaning to try another types of porous plates too: sintered glass, zirconia or alumina.