I think this is a great idea for a product, but in my experience, the pain associated with handover is something that is earned over a long period of time. Knowledge starts to centralise in one person and they don’t do enough to disperse it. Maybe they are too busy, maybe they don’t value documentation, maybe it’s an oversight, there are lots of reasons. But that problem starts to build up and you only discover the full extent of it when they leave and it hits you all at once.

A better solution to this problem would be to improve detecting this problem so you can address it in its early stages instead of when it gets bad. One way of doing this is mandatory time off. I don’t recall who said it first, but time off is chaos monkey for people. It’s common in some industries for employees to be forced to take time off to intentionally cause their normal tasks to be performed without them. For instance, banks use it to detect fraud, because the same person doing the same task all the time can make it easy for them to cover crimes up.

If your team is stuck in a rut and the same person is always responsible for doing important tasks every time, this is a risk. If they took some time off, this would help you figure out what knowledge is centralised with them. Don’t put their tasks off and wait until they get back. Figure out how to do it without them. If you struggle, that’s a clear sign you’ll be in for pain when they eventually leave for good and shows you what knowledge they need to disperse.