As pointed to me by a friend, this is one reason not to give in to the convenience of the secrets manager you already use.
My use case for fnox with keepassdb back-end was partially validated but as I mentioned elsewhere in the thread, having to set master password in an env var is a bit of snag for the workflow.
i know other people partitioning their secrets into multiple keepassx vault files, so the argument about using the same password manager can be interpreted differently.