Rather annoyingly a
forum thread asking whether it was possible to use Horizons tech for non-atmospheric planets and Odyssey tech for new atmospheric planets got closed by the moderators before I had a chance to post the following. Since I've written it now I figured I might as well post it here.
I was thinking about this myself actually but I also doubt it's technically possible. Odyssey will be using a significantly different version of the Cobra engine to Horizons. Even if it was possible to have both versions of Stellar Forge built into the Elite: Dangerous client (invoking one to generate the new atmospheric planets and one to generate the old Horizons planets), I doubt the Horizons verision would run with the newer Odyssey Cobra libraries and game code. No ... the way forward is just to do a bit more work on the new planetary tech and get it to produce more of those big terrain features like ravines and ridges and sharp edged mesas and cliff tops that were so awesome in Horizons. My big fear is ... will they? Another terrain reshuffle at this stage would mean re-baking the positions of all the surface bases amd settlements ... again. Will Frontier be bold enough to do that just for the sake of improving surface tech which they deemed suitable for release but which a part of the community has identified as being inferior or will they just stick to their guns and hope we get used to it (it's not truly terrible after all, if we hadn't seen the best that Horizons had to offer I doubt we'd be complaining).
Be bold Frontier! It'll be worth it in the long run!