Can I delete a second master key?

When I set up a new installation at iPad , I occasionally put a new key instead of the used one.
The second master key synced to other devices.

How can I keep one master key and delete the second?

YES, unuseed keys should be possible to get deleted!

Currently I don’t see an option to delete.
Neither at MacOS, nor at Android or iOS.

This topic is a duplicate of Delete E2EE Master Keys.

Closing this one. Head over there for all further discussions.