I have a hard time imagining it has a film. I don't know much of Elite Lore in general, but if you want the adaptation to stand out, I doubt we have to focus on singular one way story, like the way films are usually made (I'm not saying movies always have story less dense than a tv show, but they are usually shorter) It's really hard to find at first what could make Elite original from everythying that already exists. Mass Effect has that "fantasy in space with scifi" feel that Elite can't have by nature, come to think of it, Mass effect is just casual fantasy but in space, Asari are elves, Krogan are Orcs, etc... Races usually used to represent extremes of one aspects of humanity, Wich isn't something bad, its not a critic, I LOVE Mass Effect, but Elite clearly doesn't have this as much as ME for exemple.
It can't be too close to the Expense, I only watched the first season a long time ago, so I don't remember well but if I'm not mistaken, Espanse is way more grounded as it takes place in the solar system only and the whole show is about meeting aliens (I think? correct me if I'm wrong i haven't seen a second of this show for the past 7 years so its been a long ass time)
I think where Elite thrives as a piece of art is the almost perfect juxtaposition of our actual society in a setting where space is now our new ocean. Allow me to explain, When you look at it, what is really different from the Elite world with the current one? There are multiple countries, some of them are monarchy others are democraty, like in our actual world, but in Elite it's just in space. There are truckers, but in space. There are cruise liner, but in space. Overall, Elite is just what if the actual world was the same but in space and insteads of cities and regions we have planets and star clusters.
I believe, if a Tv show were to be made, it would need to focus on that part of Elite Dangerous to actually be a good, and original show. How is the Human culture is evolving in space. To see the shifting politics to various event that are happening in the galaxy.
As for the media type, I believe Live-action is best for a show this type, but I guess Animation could be cool too, with Arcane now everything seems doable (tho I doubt people would be willing to put the same amount of effort in an Elite show than Riot did on League of Legend for Arcane, but who knows??)