Yeah. I've been reading semi-firm to hard sci-fi my whole life, so I can believe in some pretty wild concepts like wormhole traveler or turning gas giants in to fusion torch-ships, but even wormholes can at least exist in the math, albeit not anything like they're described in sci fi. One of the "rules" of scifi, especially hard sci-fi, is you should try to keep the scope of your made up technology limited enough to be comprehensible and believable to the reader. Like bruh, if you can turn individual protons in to space battleships what do you need a planet for? That implies a level of physical mastery over the universe beyond the wildest imaginings of most sci fi. Why not miniaturize your whole civilization in to little proton brains or something? It's just so out there that it opens up too many questions and possibilities.

Like when Herbert did Dune everything ran on the Holtzman effect, and it was responsible for folding space for FTL travel, shields, and anti-grav. And that was pretty much the limits of what it did - Two key conceits that made the story possible. Gundam's thing is Minovsky Particles, which they use for a bunch of stuff including justifying why mechs have to fight at knife-fighting distances in space with beam guns and swords instead of just launching high speed missiles from light seconds away. They use it to justify their compact fusion drives, some beam guns, and a few other things.

But both those cases sorta kinda make some kind of sense. Like yeah whatever space is wacky and everyone has at least heard of wormholes that connect two points in space that are otherwise very distant. And anti-gravity is weird, but Herbert is judicious about what it does - floating flashlights, personal shields that are just fancy bucklers for Errol-Flynn style sword fights, and weird schizo-tech like an anti-gravity cart drawn by oxen to highlight the deliberate technological stasis imposed by the LANSRAAD on their serfs to maintain control. Minovsky Particles mostly just justify having giant robots fighting at close range, and not being able to use guided missiles or precision long-range munitions.

But proton battleships with omniscient perfect knowledge of the entire planet? What does that even mean? What are the limits on that? If you could shrink people down so small they can inhabit a proton somehow, what do you need a wet planet for?

Never mind that "String Theory" is bupkiss that never produces anything...

For "Dark Forest" premises I consider much, much more compelling (One of them sent me in a three day long existential crisis and still gives me the willies) I'd suggest Peter Watt's Blindsight This is the existential crisis one. It is terrifying in a way nothing else I've ever encountered is. The story itself is scary, but the concepts invoke that kind of deep dread you get in the pit of your stomach when you're stuck an in earth quake and know you are totally, utterly powerless in the grip of forces beyond your control. The other series is Alastair Reynold's "Revelation Space". Both of them deal with some really weird transhumans, the Dark Forest (in two very different but equally frightening ways), a lot of weird speculative technologies, and some very memorable characters.

I had a funny memory. I forget what story it was, maybe one of the hitchhiker stories, but the FTL drive worked by blowing the ship up to truly immense proportions, vastly larger than the entire galaxy, moving a minute amount relative to the ship but vast distances relative to the galaxy, then shrinking it back down to something more reasonable. Easily most fun, silly spoofs on FTL I've run in to.