Nick Mathewson:
Every network parameter has a default value; IIUC, unless at least three authorities are voting for some value, everybody will use the default. It's normal for the authorities not to vote for a different value if they all think the default is reasonable.
The default for these parameters is in param-spec.txt at https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/param-spec.txt#L1...
thank you Nick for explaining this, nusenu