How do you define disposable or ephemeral identity in a person context?

The terms disposable and ephemeral are strategic terms to be used when it serves a political purpose.
It is wise to use disposable now in times of extremely low trust of citizens in .gov and institutions.
Should we be able to actually install/grow a better system with our own values embedded in the architecture we can move to ephemeral.

In a person context disposable Id means that from an identity that is under full control of a person the wallet/device is able to produce from that identity as a basis numerous separate identities that have the capacity to broker contracts with any service provider. Each smart contract and valid between that disposable identity and the service provider. Part of that smart contract is a unique identifier that is able to identity the proper SSI Identity in case of breach of contract (ie non payment). So we are talking accountability and pseudonymity over anonymity as I believe this framework is the logical basis for a society. In that society there is no more state, only citizens, services and generic infrastructure services that are paid from a percentage (15-20%) on any smart contract.
We need custodians to make sure citizens can recover lost keys.
We need a disposable Id SDK/app.
We need a device fully under control of this framework, from the chip up, guaranteeing unicity from the unique hardware properties of each individual chip.
We need new generic service providers with regulatory and disciplining powers.

How do you define disposable or ephemeral identity in a IoT context?

A device will only be allowed to operate within our zone/framework if it passes the security requirements at the stage in which all devices are tested for ell cortical safety. It needs to have a similar architecture as the person ID. Private keys in the smart home context are merged with the person ID. In all other cases the private keys are merged ‹with the generic service providers.
By regulating the routers and installing the same architecture the devices appear to anyone outside of the home with disposable ID. So they do in a smart city context.

Is it important? Why?

It is the only way to sustain a society for everyone. The alternative – doing what we do now – will lead to a few smart zones (gated communities) and Mad Max in between.

What are the technical, social, commercial, political barriers to adoption?

The greed of companies. The stupidity and deviousness of politicians. The lack of awareness of c citizens.

How does disposable/ephemeral identity maintain privacy while fulfilling assurance requirements?

Disposable ID maintain pseudonymity. People are free to engage in smart contracts. There are obligations and benefits. If these are balanced people can go through life being unknown as individuals to any service provider. If a person does not fulfill a monetary obligation to a particular service provider that service provider can trace that person and expose his/her obligations.