preferredClientStatusPeriod
Value from at.asitplus.openid.IssuerMetadata.preferredClientStatusPeriod. If the field is present then the Wallet Unit SHALL send the WIA available to them with (client_status.exp - current time) - preferred_client_status_period as small as possible but non-negative. If no such WIA is available to the Wallet Unit, it SHALL request a new WIA from the Wallet Provider that satisfies client_status.exp - current time >= preferred_client_status_period.