It happens. I also had a few people come back. An entire team quit (4 people) to go work for a competitor. Two came back when the competitor screw them over, offering higher wages just for 3 months, and then linking the wages to an impossible schedule.
One manager quit because of stress and came back a few years later for a similar job with a few less responsibilities.
You can have multiple identities, just as you can have them in chrome without being logged in.
search for Firefox Multi-Account Containers.
OR https://support.mozilla.org/en-US/kb/profile-manager-create-...
But you can always create a shortcut for each identity...I use this method for Brave.
https://draw.io
But dbdiagram.io looks amazingly easy to use.
And so are the rest of the suggestions.
I also realize that I don't use UML with draw.io:)