Ability to edit the raw HTML of the generated payslip

This feature does not exist, I would like to edit the raw HTML of the payslips. Under settings > payslip customisation.
It should be easy to take out table data, and replace with your own wording. For example "Pension Contribution (5% of £XXX)" to "Pension Contribution"
Also, if you click under the CSS Settings, "Append to default", the textbox is so narrow you can barely see what you're typing, and it doesn't give the option to enlarge it.