Hey - this looks awesome, especially now that more folk are having to embrace remote working - definitely going to be trying it out. And welcome to the frontend ;-)
One thing that often happens when folk move on is that they pass out their contact details - usually email address to enable people to keep in touch with them - does thankbox allow the recipient to send a message to all those that contributed? This would allow them to express thanks (should they want to!) and possibly share contact details.