In SERVER-99351 we introduced a new API for feature flag checks, which in addition to requiring passing a FCVSnapshot ("node-local FCV"), it also requires passing a VersionContext ("Operation FCV") obtained from the operation's OperationContext.

This ticket is for determining the performance implications of the new API, in particular:

• On average, is a significant fraction of a typical operation's time spent in feature flag checks?
• If checking feature flag checks is a hot path, the new API requires getting the VersionContext decoration from the OperationContext, and incorporating it into the feature flag check logic. How much overhead does this have?
• If the overhead is significant, can we optimize feature flags in some way to mitigate the impact?