Thanks for your quick reply !
In my last company, we used a tool (Jorani) which is not a WordPress plugin but allow to export a .ics calendar with the leaves of all the company, or just own. (online ics, with updates).
This is very usefull, because you can import it into your Outlook and superimpose your work calendar with the calendar with leaves to think about when you’ll ask a new leave.
You can also see your colleagues leaves from Outlook, when you have to plan a meeting or contact them, you can know if they are out or not.
I think it could be a new feature for WPERP, I hope it could be very usefull for all users.
If you want i can send you some screens 🙂