Which is why I’m immensely disappointed by the fact that you don’t actually have to do any of this. Aren’t you?
The existence of not one, but two cheese methods for the game’s ultimate challenge, is something I personally consider a tragedy.
The first culprit, belt buffering, allows players to simply collect promethium and bring it back to Nauvis where the other ingredients will be waiting. And the second option, overgrowth soil recycling, lets them store biter eggs in an unspoilable form.
You may notice that these two have something in common: They both remove spoilable cargo from the equation. Speed no longer matters. Instead of needing a ship with both speed and firepower, now you only need firepower. I’m not saying this is necessarily easy to do, but I am saying it’s simple. All it takes is an enormous behemoth ship. It doesn’t matter if it’s as slow as a rock, there’s no pressure at all. Do you see how the elegant challenge was reduced to a simple resource grind? I don’t know about you guys, but I kind of hate it.
“But OP, if you don’t like it, then just don’t do it.”
Yes, I’m aware that anyone can play the game any way they want. Challenges, settings, mods… They all exist to let people customize their experience to their liking. But this is a board about balancing. And that means balancing the default, intended experience, with the goal of making it better for the average player. And I believe that the reduced difficulty of promethium science is making the game worse.
How can we make it better? Well, it’s quite simple:
1) Promethium needs to be impossible to store. The spoilage mechanic already exists for this purpose, so we can just apply it here. Promethium is an unstable radioactive element, after all. When the ship breaks it into small chunks, those chunks should begin to quickly decay into useless rock. The length of the timer doesn’t matter, as long as it’s significantly shorter than the biter egg timer. The promethium only needs to go from the collector to the core of the ship. That can only take minutes at most, nobody will ever realistically have to worry about losing their promethium to spoiling.
2) It should be impossible to store biter eggs in an unspoilable form. Make overgrowth soil recycle into itself, so biter eggs can’t be extracted back out of it. Landfill actually recycles into itself, so it wouldn’t be unprecedented. There is, however, one very odd alternate possibility here, which requires some more thought: Productivity 3 modules can also be recycled for biter eggs. Compared to overgrowth soil, they are extremely expensive and offer terrible storage density, so I doubt anyone would be crazy enough to try to use them as a storage method, but you never know… In case this method shows signs of being viable, then the issue can be solved by manually removing biter eggs from the module’s recycling recipe. It’s not elegant, and I hope it doesn’t become necessary, but it would accomplish its mission…
Some of you may notice that this is actually a compiled version of two posts I’ve previously made in the suggestions board. Why did I do this? Well… At the time of making those posts, I was actually not aware of the balancing board’s existence

But as soon as I noticed it, I realized that the topic discussed in those posts would be much more appropriate for this board, rather than the suggestions one. So I moved them here, and took the opportunity to clean them up and update them with some more thorough argumentation. I do sincerely hope that this isn’t an annoyance to anyone, or worse, breaks some rule that I failed to notice.