Establish a strategy to shard off feature flags from the Redis cache instance

This issue follows #2143 (closed) as it is a good exercise to think through the typical considerations of Redis migration. We need to establish (at least) the following points of our plan:

• Is the redis.yml configuration file being introduced on &886 apt for this effort?
• Should we consider provisioning this cluster on k8s?
• What is our tolerance for data loss on this feature, and how does that impact our data migration strategy?