When designing a CI solution to isolate specific workloads for security, it is essential to consider multi-tenancy. Multi-tenancy enables multiple tenants (such as different users or teams) to use the same infrastructure while keeping their workloads isolated and secure. This isolation ensures that the data and processes of one tenant do not interfere with another, maintaining a secure environment. High Availability, Fault Tolerance, and Redundancy, while important for system reliability and uptime, do not specifically address the need for workload isolation for security purposes.

During the cloud design assessment, it is critical to ensure that sufficient consumer resources exist to support application elasticity. This means there must be enough computing resources available to handle the scaling of applications as triggered internally by the developers. Without adequate resources, the self-scaling mechanism cannot function properly, leading to performance issues or application downtime.

When designing a packaged PaaS solution with the primary concern of application portability, the focus should be on selecting technologies that enable portable PaaS architectures. This typically includes technologies like operating system containers, PaaS frameworks, and container-orchestration-based approaches which ensure that applications can be easily moved and run in different environments. Therefore, the consideration that focuses on portability is choosing a technology that enables portable PaaS architectures.