Basically yes - I want to replace supla cloud. Thanks to this I will bind OpenHab with supla devices. Thanks to this I will be able to control Suplas with my OpenHab application (either web or mobile), because for us it will be only things (OpenHab nomenclature)
Then make a decision whether you want the binding to talk to the Supla server (the easier, but still not easy option) or have the devices talk to your binding without the use of the Supla server.
That’s about what I can tell. If you’re a seasoned programmer and like a challenge then I would say go for it. Because a challenge it will be; there seems to be no documentation at all.
So unless you already bought a lot of Supla devices, I would consider a different technology.