Buy the upgrade that shortens your next full loop
Use criteria first: compare Strength, Cash, Cutter speed, and rebirth timing, then enter your own values in the resource calculator before spending.
The game officially names Cutters and Upgrades, but it does not publish a public stat table in the selected source set. Use criteria first: compare Strength, Cash, Cutter speed, and rebirth timing without invented names, costs, effects, or rarity odds. That makes a bottleneck method more reliable than a guessed tier order; use the resource calculator with player-input values from your own screen before spending.