To keep track of obsolete features in the code rather than somewhere else, what about suppressing the obsolete call warning when the corresponding obsolete message has a time stamp in the future?

With such a convention, it would be possible to keep the obsolete mark for `type_name`. If the time stamp would be set to [2020-05-31], the warning would not be reported by EiffelStudio 19.11 until June 2020. This should give sufficient time for migration to the new version of EiffelStudio.

The exact convention about the grace period could be discussed a bit deeper if needed.