naive even fill to limit

const input = [ 
  [ 1, 2, 3 ],
  [ 4, 5 ],
  [ 6, 7, 8, 9 ],
  [ 10 ],
  [ 11, 12 ],
  [ 13, 14, 15, 16, 17 ] 
]
const outputLimit = 12
const chunkLimit = 2

function fill(input, outputLimit, chunkLimit, output=[], innerIndex=0) {
  const maxIndex = outputLimit - output.length
  const toRemove = []
  input.forEach((list, i) => {
    if(i >= maxIndex) return
    const item = list[innerIndex]
    if(item === undefined && list.length <= innerIndex) {
      toRemove.push(i)
    } else {
      output.push(item)
    }
  })
  input = input.filter((_, index) => toRemove.indexOf(index) === -1)
  innerIndex++
  if(output.length === outputLimit || input.length === 0 || innerIndex === chunkLimit) {
    return output
  } else {
    return fill(input, outputLimit, chunkLimit, output, innerIndex)
  }
}
console.log(input)
console.log(fill(input, outputLimit, chunkLimit))