After thinking about the design for a bit, I don't know if the 4 poles are motors or not. Not sure if the space can allow magnets and voice coils inside. If not in the poles then the voice coil should be under the two diaphrams, not sure if seperated magnets for two diaphrams or same magnet for two diaphrams. The first gif on technology section shows nothing in between two diaphrams.
The fourth gif shows there are springs at the poles, not sure if those are the only components working as spider. They do claim very linear Kms, I am not experienced enough to know if normal metal springs are more linear than cloth spiders. The sliding mechanism will likely create noise if they are centered using metal, not cloth like other manufacturers.
The only thing they have not solved is surround issue. With small cone area and high excursion, the surround will make radiating area different for going outwards and inwards.