Does anyone know of this software, which looks amazing btw, is still being developed?
Unfortunately no. It's kind of abandonware you still have to pay for.
From what I have understood, if someone were to gather thousands of generous Twitch streamers, they purchase it beyond the asking price, and end up making this program the greatest video background generator ever, then the developer might create a completely different version of a landscape creator program from scratch because patching and adding more addons and features is getting extremely difficult. Especially adding an export feature. Adding that alone would be a monumental task involving a propitiatory compressive algorithmic file extension creator, and the means to convert it to a compatible file format! It would take years for him to create it all by himself.
So yeah, further development is halted until a miracle happens for it.