Currently, if you have 16 hands for a recipe you'll see estimated performance 60
But if you have 17 hands, you'll see 63.75 which is not possible unless you mix items on belts

I would like to see performance assuming you don't mix items in a single hand

function getCraftingTime(recipe: number[], hands: number): number {
  if (hands < recipe.length) return Infinity;

  const assigned = new Array(recipe.length).fill(1);
  let remaining = hands - recipe.length;

  while (remaining > 0) {
    const worstTime = Math.max(...recipe.map((qty, i) => qty / assigned[i]));

    for (let i = 0; i < recipe.length; i++) {
      if (recipe[i] / assigned[i] === worstTime) {
        assigned[i]++;
        remaining--;
        if (remaining === 0) break;
      }
    }
  }

  return Math.max(...recipe.map((qty, i) => qty / assigned[i]));
}