Nice chip! I did not knew that one although I am of the CMOS era!

Anyway, since you master the art of software, I think is waste of money to add hardware when you can debounce in software.

Plenty of ways to do that and as you said, going into production, will save you a lot of money and complexity.

One example. Read all buttons in an array. After a period of say 10ms, read again and compare all the buttons. One pass, reading and debouncing all buttons.

Ioannis