Poor rendering for colSpan and rowSpan cells with empty chars

[dfoverdx]

I'm trying to print a table without borders between rows where some cells have a colSpan = 2. I've set my chars values according to the documentation:

const table = new Table({
  head: [],
  chars: { mid: '', 'left-mid': '', 'right-mid': '', 'mid-mid': '' },
})

I end up with ┬ for each cell with a colSpan with no characters between them. As far as I can tell, there's no way to specify the character for inner column splits, so I end up with this.