Currently it is not possible to ask for a rotation of the master password.
I’m curious to hear what risk do you think this is reducing. Unlike other password managers, or regular applications, the mater password is used to encrypt the private key locally. It never leaves the device. An attacker that would have access to the master password would still need access to the key. For an attacker that have access to the private key, it wouldn’t matter if you rotate it, since it wouldn’t rotate for the attacker.