Thanks for catching this! You're right, it was a numerical overflow — the output multiplier had no upper bound, so pushing Stardust that high broke the math.
Just shipped a hotfix: Sector Warp now grants at most +1 Stardust per warp and is rate-limited to one warp every 10 seconds, so it's not possible to snowball like that anymore. The multiplier formula is also hard-capped now so it can never hit Infinity again, even in extreme edge cases.
Appreciate you testing it this hard, honestly helped a lot — let me know if you spot anything else weird!