Overloading an abstract attribute with a Final one

In the following code it would be useful to mark toto as final to make sure no code modifies it by error. However this triggers Cannot override writable attribute "toto" with a final one

from typing import Final

class Base:
    toto: str = NotImplemented
    def access_toto(self) -> str:
        return self.toto

class CmdA(Base):
    toto: Final[str] = "toto"

In fact I tend to agree with that error, in that what I'd really like to do is to annotate toto as "abstract final", which is not possible either as the use of toto: Final[str] triggers Final name must be initialized with a value, and toto: Final[str] = NotImplemented still gets the
Cannot override final attribute "toto" (previously declared in base class "Base") the previous attempt also showed.

• Mypy version used: 1.1.1, 0.812
• Python version used: 3.9.2

Start by reproducing the supplied example with mypy 1.1.1 and 0.812, then compare the diagnostics for Final attributes and inheritance. No files or tests are named in the report; done requires an agreed interpretation of abstract-final attributes and corresponding behavior or diagnostics.