Working for a large organization means frequently you have to offboarding deprecated apps. I think it would be usefull if the portal offboard.mendix.com has an offboard-screen where you can see the status of the offboarding process. I have 2 suggestions:
1) when making an offboard request: a warning if one of the environments (or more) are still running before you can submit the request
2) a separate status-screen where all the running and previous offboarding requests are listed, just like the support.mendix.com portal. Or list them on support.mendix.com.