> they might not include staff time and incidental costs around cash transactions that aren't obvious because they're not linked to the individual transactions, such as reconciliation, time spent transporting the cash, costs of depositing the cash, insurance to cover storage of cash.

Yep. I worked as a supervisor in retail for a number of years and here's a list of cash handling costs that dont exist with card payments:

Making change on each transaction

Counting cash drawers in and out for each employee shift

Preparing daily bank deposits

Going to the bank to make deposits and get new change

Theft (by employees, external theft wasnt a problem for us)