If you want your game to run around .009 FPs ue5 is a wonderful idea.
For any real project, any real engine would probably be your best bet…
Meaning CryEngine, Godot, maybe even Unity considering that they actually have some decent people who listen to your bug reports, unlike Epic.
Voxel terrain done well will likely require customization of the engine.
In fact, it’s rare to see it done well.
No man’s sky has an interesting example, but it also tends to go away between loading.
To be able to preserve it you’d have to be able to load it somewhere, and in that particular game it could mean an almost infinite stream of data…