It’s not, which is why it’s proceeding very slowly. That and the huge # of PRs people throw at the project, 300+ PRs in the last month, holy crap. It’s the main thing I’m working on when I’m not merging or bugfixing.
That number is touching one of the most performance critical parts of the entire game, turning it into a number configured at run-time would not only be a pain in the ass code wise, but would likely slow down the game even if you don’t change it.
You may not realize this, but you’re literally asking for the game to do something like 4x as much work to handle this one thing.
tl;dr, there are good reasons the reality bubble is not bigger than it already is, someone might be able to experiment with upping it and see what bugs crop up and how it’s handled performance wise, but I wouldn’t hold my breath.